A chemically amplified positive resist composition comprising a polymer PB and a polymer PA, said polymer PB comprising recurring units of the general formulae and: wherein A is a single bond or a C 1 -C 10 alkylene group which may be separated by an ethereal oxygen atom, R 1 is each independently hydrogen or methyl, R 2 is each independently a C 1 -C 6 alkyl group, B 3 is a linkage selected from the group consisting of a straight or branched C 1 -C 10 alkylene group which may contain an ethereal oxygen atom, R 3 and R 4 are each independently hydrogen or a monovalent C 1 -C 10 hydrocarbon group which may contain a heteroatom, with the proviso that R 3 and R 4 are not hydrogen at the same time, R 3 and R 4 may bond together to form a ring with the nitrogen atom to which they are attached, and R 3 and R 4 are a divalent C 2 -C 12 hydrocarbon group which may contain a heteroatom when they form a ring, B 3 may bond with R 3 or R 4 to form a ring with the nitrogen atom to which they are attached, and in this case, the nitrogen-containing ring is a 5 to 7-membered ring which excludes a ring of the structure that a lone pair of the nitrogen atom renders the nitrogen-containing ring aromatic, and the nitrogen-containing ring is not an aromatic ring, a is an integer of 0 to 4, b is a positive integer of 1 to 5, p and q are each independently 0 or 1, t is an integer of 0 to 2, with the proviso that when q=0, the atom in B 3 that bonds with a main chain carbon is an ethereal oxygen atom and B 3 should contain at least two consecutive carbon atoms originating from an alkylene group, said polymer PA comprising recurring units having an acidic side chain protected with an acid labile protective group and recurring units of the general formula: wherein D is a divalent C 1 -C 15 hydrocarbon group in which some or all hydrogen atoms may be substituted by fluorine atoms or any methylene moiety may be substituted by an ethereal oxygen atom or carbonyloxy radical, R 1 is as defined above, R 5, R 6 and R 7 are each independently a substituted or unsubstituted, straight or branched C 1 -C 10 alkyl, alkenyl or oxoalkyl group, or a substituted or unsubstituted C 6 -C 18 aryl, aralkyl or aryloxoalkyl group, any two of R 5, R 6 and R 7 may bond together to form a ring with the sulphur atom, and v is 0 or 1. wherein A is a single bond or a C 1 -C 10 alkylene group which may be separated by an ethereal oxygen atom, R 1 is each independently hydrogen or methyl, R 2 is each independently a C 1 -C 6 alkyl group, B 3 is a linkage selected from the group consisting of a straight or branched C 1 -C 10 alkylene group which may contain an ethereal oxygen atom, R 3 and R 4 are each independently hydrogen or a monovalent C 1 -C 10 hydrocarbon group which may contain a heteroatom, with the proviso that R 3 and R 4 are not hydrogen at the same time, R 3 and R 4 may bond together to form a ring with the nitrogen atom to which they are attached, and R 3 and R 4 are a divalent C 2 -C 12 hydrocarbon group which may contain a heteroatom when they form a ring, B 3 may bond with R 3 or R 4 to form a ring with the nitrogen atom to which they are attached, and in this case, the nitrogen-containing ring is a 5 to 7-membered ring which excludes a ring of the structure that a lone pair of the nitrogen atom renders the nitrogen-containing ring aromatic, and the nitrogen-containing ring is not an aromatic ring, a is an integer of 0 to 4, b is a positive integer of 1 to 5, p and q are each independently 0 or 1, t is an integer of 0 to 2, with the proviso that when q=0, the atom in B 3 that bonds with a main chain carbon is an ethereal oxygen atom and B 3 should contain at least two consecutive carbon atoms originating from an alkylene group, said polymer PA comprising recurring units having an acidic side chain protected with an acid labile protective group and recurring units of the general formula: wherein D is a divalent C 1 -C 15 hydrocarbon group in which some or all hydrogen atoms may be substituted by fluorine atoms or any methylene moiety may be substituted by an ethereal oxygen atom or carbonyloxy radical, R 1 is as defined above, R 5, R 6 and R 7 are each independently a substituted or unsubstituted, straight or branched C 1 -C 10 alkyl, alkenyl or oxoalkyl group, or a substituted or unsubstituted C 6 -C 18 aryl, aralkyl or aryloxoalkyl group, any two of R 5, R 6 and R 7 may bond together to form a ring with the sulphur atom, and v is 0 or 1.