A sulfonate of the formula (I): ##STR1##

wherein Q¹, Q², Q³, Q⁴ and Q⁵ each independently represents a certain substituent, and A⁺ represents a counter ion,

with the proviso that at least one of Q¹, Q², Q³, Q⁴ and Q⁵ is a group of the formula (II) ##STR2##

wherein R¹ and R² each independently an alkyl having 1 to 12 carbon atoms or the like; and

a chemical amplification type positive resist composition comprising the sulfate of the formula (I) and

a resin which contains a structural unit having an acid labile group and which itself is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid.