The present invention relates to a naphthalimidobenzamide derivative represented by the following formula (1):
(wherein, R1 represents a hydrogen atom, etc., Y represents a hydrogen atom or -CON(R4)-A2-X2, R2 and R4 are the same or different and each independently represents a hydrogen atom, etc., A1 and A2 are the same or different and each independently represents an alkylene group which may be interrupted at least once by -N(R3)- (R3 representing a hydrogen atom, etc.) and X1 and X2 are the same or different and each independently represents a (hetero)aryl group which may have a substituent, etc.) or salt thereof; and a pharmaceutical comprising it as an effective ingredient. The compound is useful as an antitumor agent and the like.