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The alicyclic hydrocarbon acid-decomposable resin may contain a plurality of repeating units each containing a lac› tone group. In this case, it is preferred for the acid-decom› posable resin to contain either (1) any one of those of general formula (AI) in which Ab is a single bond together with any one of those of general formula (AI) in which Ab is -Ab$_{1 }$ - CO$_{2}$ -, or (2) a mixture of two of those of general formula (AI) in whichAb is -Ab$_{1}$-CO$_{2}$-. 

The content of repeating unit containing a lactone group (when there are a plurality of repeating units each containing a lactone group, the sum thereof), based on all the repeating units of the resin (B), is preferably in the range of 10 to 70 mo! %, more preferably 20 to 60 mo! %. 

It is preferred for the alicyclic hydrocarbon acid-decom› posable resin according to the present invention to have a repeating unit having an alicyclic hydrocarbon structure sub› stituted with a polar group. The containment of this repeating unit would realize enhancements of adhesion to substrate and developer affinity. The polar group is preferably a hydroxyl group or a cyano group. 

The hydroxyl group as the polar group constitutes an alco› holic hydroxyl group. 

As the alicyclic hydrocarbon structure substituted with a polar group, there can be mentioned, for example, any of the structures of general formulae (VIIa) and (VIIb) below. 

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In general formula (VIIa), 

each of R$_{2}$c to R$_{4}$ c independently represents a hydrogen atom, a hydroxyl group or a cyano group, provided that at least one of the R$_{2}$c to R$_{4}$ c represents a hydroxyl group or a cyano group. Preferably, one or two of the R$_{2}$c to R$_{4}$ c are hydroxyl groups and the remainder is a hydrogen atom. More preferably, two of the R$_{2}$c to R$_{4}$c are hydroxyl groups and the remainder is a hydrogen atom. 

The groups of general formula (VIIa) preferably have a dihydroxy form or monohydroxy form, more preferably a dihydroxy form. 

As the repeating units containing any of the groups of general formula (VIIa) or (VIIb ), there can be mentioned the repeating units of general formulae (II-AB!) and (II-AB2) above wherein at least one of R13’ to Rl 6’ has any of the groups of general formula (VIIa) or (VIIb) as well as the repeating units of general formula (Alla) or (AIIb) below. As examples of the former repeating units, there can be men› tioned the structures in which R$_{5 }$ ofthe----COOR$_{5 }$ represents any of the groups of general formula (VIIa) or (VIIb ). 

