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1 to 5 carbon atoms; R 81 represents an alkyl group; R 82 represents a group which forms an aliphatic monocyclic group with the carbon atom to which R $^{82 }$is bonded; R 83 represents a branched alkyl group; R$^{84 }$represents a group which forms an aliphatic polycyclic group with the carbon atom to which R$^{84 }$is bonded; R$^{85 }$represents a linear alkyl group ofl to 5 carbon atoms; R$^{15 }$andR$^{16 }$each independently represents an alkyl group; Y 2 represents a divalent linking group; and X $^{2 }$represents an acid dissociable group. 

In the formulae, R, Y 2 and X 2 are the same as defined above. 

In general formula (al 1-0-11), as the alkyl group for R 81 , the same alkyl groups as those described above for R$^{14 }$in formulae (1-1) to (1-9) can be used, preferably a methyl group, an ethyl group or an isopropyl group. 

As the aliphatic monocyclic group formed by R $^{82 }$and the carbon atoms to which R 82 is bonded, the same aliphatic cyclic groups as those described above for the aforemen› tioned tertiary alkyl ester-type acid dissociable group and which are monocyclic can be used. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3- to I I-membered ring, more preferably a 3- to 8-membered ring, still more preferably a 4- to 6-membered ring, and most preferably a 5- or 6-membered ring. 

The monocycloalkane may or may not have part of the carbon atoms constituting the ring replaced with an ether bond (---0-). 

Further, the monocycloalkane may have a substituent such as an alkyl group of 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group of 1 to 5 carbon atoms. 

As an examples ofR $^{82 }$constituting such an aliphatic mono› cyclic group, a linear alky lene group which may have an ether bond (---0-) interposed between the carbon atoms can be given. 

Specific examples of structural units represented by gen- era! formula (all-0-11) include structural units represented by the aforementioned formulas (al-1-16) to (al-1-23), (al- 1-27) and (al-1-31). Among these, a structural unit repre› sented by general formula (all-1-02) shown below which includes the structural units represented by the aforemen› tioned formulas (al-1-16), (al-1-17), (al-1-20) to (al-1-23), (al-1-27), (al-1-31), (al-1-32) and (al-1-33) is preferable. Further, a structural unit represented by general formula ( al 1- 1-02’) shown below is also preferable. 

In the formulas, h represents an integer of 1 to 4, and preferably 1 or 2. 

[Chemical Formula 51] 

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In the formulae, Rand R $^{81 }$are the same as defined above; and h represents an integer of 1 to 4. 

In general formula (al 1-0-12), as the branched alkyl group for R 83 , the same alkyl groups as those described above for R $^{14 }$in formulas (1-1) to (1-9) which are branched can be used, and an isopropyl group is particularly desirable. 

As the aliphatic polycyclic group formed by R $^{84 }$and the carbon atoms to which R $^{84 }$is bonded, the same aliphatic cyclic groups as those described above for the aforemen› tioned tertiary alkyl ester-type acid dissociable group and which are polycyclic can be used. 

Specific examples of structural units represented by gen› eral formula (all-0-12) include structural units represented by the aforementioned formulas (al-1-1-26) and (al-1-28) to (al-1-30). 

As the structural unit (al 1-0-12), a structural unit in which the aliphatic polycyclic group formed by R $^{84 }$and the carbon atom to which R $^{84 }$is bonded is a 2-adamantyl group is pref› erable, and a structural unit represented by the aforemen› tioned formula (al-1-26) is particularly desirable. 

In general formula (al 1-0-13), Rand R$^{84 }$are the same as defined above. 85 

As the linear alkyl group for R , the same linear alkyl groups as those described above for R$^{14 }$in the aforemen› tioned formulas (1-1) to (1-9) can be mentioned, and a methyl group or an ethyl group is particularly desirable. 

Specific examples of structural units represented by gen- eral formula (all-0-13) include structural units represented by the aforementioned formulas (al-1-1), (al-1-2) and (al- 1-7) to (al-1-15) which were described above as specific examples of the structural unit represented by general for- mula (al-1). 

As the structural unit ( al 1-0-13 ), a structural unit in which the aliphatic polycyclic group formed by R $^{84 }$and the carbon atom to which R $^{84 }$is bonded is a 2-adamantyl group is pref› erable, and a structural unit represented by the aforemen- tioned formula (al-1-1) or (al-1-2) is particularly desirable. 

Further, a compound in which the aliphatic polycyclic group formed by R $^{84 }$and the carbon atom to which R $^{84 }$is bonded is a "group in which one or more hydrogen atoms have been removed from tetracyclododecane" is also prefer- able, and a compound represented by the aforementioned formula (al-1-8), (al-1-9) or (al-1-30) is also preferable. 

In general formula (al 1-0-14), Rand R$^{82 }$are the same as defined above. R$^{15 }$andR$^{16 }$are the same as R$^{15 }$andR$^{16 }$in the aforementioned general formulae (2-1) to (2-6), respectively. 

Specific examples of structural units represented by gen› eral formula (all-0-14) include structural units represented by the aforementioned formulae (al-1-35) and (al-1-36) which were described above as specific examples of the struc› tural unit represented by general formula (al-1). 

In general formula (al 1-0-15), Rand R$^{84 }$are the same as defined above. R$^{15 }$andR$^{16 }$are the same as R$^{15 }$andR$^{16 }$in the aforementioned general formulae (2-1) to (2-6), respectively. 

-continued 

