PURPOSE: To obtain a curable resin composition having excellent heat resistance, especially thermal decomposition resistance, by compounding an epoxy resin comprising a phenolic novolac or cresol novolac epoxy resin and a curing agent comprising an aromatic imide or amide imide amine.

CONSTITUTION: The objective composition is composed of (A) a diamine of formula (Ar is bivalent aromatic group; Ar' is tetravalent aromatic group wherein 4 carbonyl groups are bonded directly to different carbon atoms; Ar" is trivalent aromatic organic group wherein 3 carbonyl groups are bonded directly to different carbon atoms and a pair of carbonyl groups are bonded to the adjacent carbon atoms of Ar' group and Ar" group; n and m are 0 or positive integer; m+n>0) and (B) a phenolic novolac or cresol-type epoxy resin. The amount of the component A is 1.2W0.7 equivalent per 1 equivalent of the epoxy group of the component B.