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The polymer of the present invention may contain a repeat- ing unit derived from a monomer having a carbon-carbon double bond other than those described above. For example, it may contain a repeating unit derived from substituted acrylic acid esters such as methyl methacrylate, methyl cro- tonate, dimethyl maleate and dimethyl itaconate; unsaturated carboxylic acids such as maleic acid, fumaric acid and ita› conic acid; cyclic olefins such as norbornene, a norbornene derivative and a tetracyclo[ 6.2.1.1 3 • $^{6 }$.0$^{2}$-7Jdodecene deriva› tive; unsaturated acid anhydrides such as itaconic anhydride; and other monomers. 

Meanwhile, the polymer of the present invention can also be used in other lithography than a lithography of an ArF exposure such as a KrF lithography, an electron beam lithog› raphy and a EUV lithography. 

The polymer of the present invention can further include, in addition to a repeating unit represented by the foregoing general formula (4) or preferably the foregoing general for- mula (5), any one or more kinds ofrepeating units represented by the following general formulae (11) to (15) and may fur› ther include any one or more kinds of repeating units repre› sented by the above-mentioned general formulae (6) to (10). 

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(In the formulae, each R 9 independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluo› romethyl group. X$^{1 }$represents an acid-labile group. G repre- sents an oxygen atom or a carbonyloxy group (-C(=O) 0-).) 

The polymer including a repeating unit represented by the foregoing general formula (11) is decomposed by action of an acid to generate a phenolic hydroxyl group and/or a carboxy› lic acid thereby giving an alkaline-soluble polymer. Various groups can be used as the acid-labile group X 1 , and specific examples of them include groups represented by the above› mentioned general formulae (Ll) to (L4), tertiary alkyl groups having 4 to 20, preferably 4 to 15 carbon atoms, trialkylsilyl groups whose each alkyl group has 1 to 6 carbon atoms, and oxoalkyl groups having 4 to 20 carbon atoms. 

Specifically, a repeating unit represented by the above› mentioned general formula (11) is exemplified by the follow- ing, but is not limited thereto. 

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