A chemically amplified positive resist composition comprising (A) a polymer adapted to turn soluble in alkaline aqueous solution under the action of acid, comprising recurring units having the general formula , and having a weight average molecular weight of 1,000 to 500,000, wherein R 14 is hydrogen, hydroxyl, straight alkyl, branched alkyl, halogen, or trifluoromethyl, R 15 is hydrogen, hydroxyl, halogen or trifluoromethyl, R 16 is C 4 -C 12 tertiary alkyl, R 17 is hydrogen, optionally substituted alkyl, optionally substituted alkoxy, -C(CF 3 ) 2 -OH, trialkylsilyl in which each alkyl moiety has 1 to 6 carbon atoms, C 4 -C 20 oxoalkoxy, tetrahydropyranyloxy, tetrahydrofuranyloxy, or trialkylsilyl, R 18 is hydrogen or methyl, R 19 is hydrogen, methyl, alkoxycarbonyl, cyano, halogen, or trifluoromethyl, R 20 is a C 4 -C 30 substituted or unsubstituted, straight or branched alkyl group or substituted or unsubstituted cycloalkyl group, u is 0 or an integer of 1 to 4, t is 0 or an integer of 1 to 5, p, r and s are 0 or positive numbers, q is a positive number, p+q+r+s = 1, (B) an alkali-soluble polymer containing a hydroxyl and/or carboxyl group and having a weight average molecular weight of 1,000 to 100,000, the polymer being soluble in an alkaline aqueous solution and having an alkaline dissolution rate of 400 to 12,000 Å/sec in 2.38 wt% tetramethylammonium hydroxide aqueous solution, (C) a photoacid generator, and (D) an organic solvent, wherein the alkali-soluble polymer (B) is selected from the group consisting of phenolic resin, urethane resin, polyhydroxystyrene, a copolymer of hydroxystyrene and a carboxyl-containing vinyl monomer, a homopolymer of a carboxyl-containing monomer, a copolymer of hydroxystyrene and a carboxyl-containing monomer, and an alkali-soluble cellulose. (A) a polymer adapted to turn soluble in alkaline aqueous solution under the action of acid, comprising recurring units having the general formula , and having a weight average molecular weight of 1,000 to 500,000, wherein R 14 is hydrogen, hydroxyl, straight alkyl, branched alkyl, halogen, or trifluoromethyl, R 15 is hydrogen, hydroxyl, halogen or trifluoromethyl, R 16 is C 4 -C 12 tertiary alkyl, R 17 is hydrogen, optionally substituted alkyl, optionally substituted alkoxy, -C(CF 3 ) 2 -OH, trialkylsilyl in which each alkyl moiety has 1 to 6 carbon atoms, C 4 -C 20 oxoalkoxy, tetrahydropyranyloxy, tetrahydrofuranyloxy, or trialkylsilyl, R 18 is hydrogen or methyl, R 19 is hydrogen, methyl, alkoxycarbonyl, cyano, halogen, or trifluoromethyl, R 20 is a C 4 -C 30 substituted or unsubstituted, straight or branched alkyl group or substituted or unsubstituted cycloalkyl group, u is 0 or an integer of 1 to 4, t is 0 or an integer of 1 to 5, p, r and s are 0 or positive numbers, q is a positive number, p+q+r+s = 1, (B) an alkali-soluble polymer containing a hydroxyl and/or carboxyl group and having a weight average molecular weight of 1,000 to 100,000, the polymer being soluble in an alkaline aqueous solution and having an alkaline dissolution rate of 400 to 12,000 Å/sec in 2.38 wt% tetramethylammonium hydroxide aqueous solution, (C) a photoacid generator, and (D) an organic solvent, <EOS>