An acidic gas absorbent contains an amine compound of formula (1) and a cyclic amino compound of formula (2) or (3): where in the formulas, each R1 is independently a straight-chain hydroxyalkyl having a hydroxy at the terminal, R2 is a branched-chain secondary alkyl group, R3 and R4 are hydrogen, hydroxy, a hydroxyalkyl or aminoalkyl, provided that at least one of R3 and R4s is a hydroxyalkyl or aminoalkyl, each p is independently an integer of 2 to 4, each R5 is independently hydrogen, hydroxy, or a hydroxyalkyl or aminoalkyl, provided that at least one of R5s is a hydroxyalkyl or aminoalkyl, and q is an integer of 3 to 8.