Provided are an epoxy resin curing agent containing an amine composition or a modified product thereof, wherein the amine composition contains bis(aminomethyl)cyclohexane (A) and a compound (B) represented by the following formula (1), and wherein the content of the component (B) based on 100 parts by mass of the component (A) is from 0.01 to 2.0 parts by mass, an epoxy resin composition, and use of an amine composition for an epoxy resin curing agent, wherein R1 represents an alkyl group having 1 to 6 carbon atoms, and p is a number of 1 to 3.