An object of the present invention is to provide a novel benzazepine compound or a salt thereof, which has excellent vasopressin antagonistic activity.The benzazepine compound or a salt thereof of the present invention is represented by Formula (1):wherein R1, R2 and R5 may be the same or different and each represents H or D; and R3 and R4 each represents a C1-6 alkyl group, a C1-6 deuteroalkyl group, or a C1-6 perdeuteroalkyl group.