The object of this invention is to provide a base generator, which generates a strong base, has a high solubility in general used organic solvents, can directly solve in base reactive compounds such as epoxy-based compounds and the like, and possesses both of high thermal tolerance and low nucleophilicity, a base reactive composition containing the base generator and a base reactive compound, as well as a method for generating a base. The present invention is related to a compound represented by the general formula (A), a base generator consisting of the compound, a base reactive composition containing the base generator and a base reactive compound, as well as a method for generating a base: wherein, R1 to R5 each independently represents a hydrogen atom, an alkyl group, an aryl group with or without a substituent, or an arylalkyl group with or without a substituent; R6 represents a hydrogen atom, an alkyl group with or without a substituent, an alkenyl group, an alkynyl group, an aryl group with or without a substituent, or an arylalkyl group with or without a substituent; R7 represents a hydrogen atom, an alkyl group with or without an amino group, an aryl group with or without a substituent, or an arylalkyl group with or without a substituent; and Z- represents an anion derived from a carboxylic acid having a specific structure.