An object of the present invention is to provide a power module having high reliability. The power module according to the present invention, includes a circuit body and a case housing the circuit body. The case has a first case member including a first base plate and a second case member including a second base plate. The first case member has a first side wall portion formed in an arrangement direction of the first base plate and the second base plate. The second case member has a second side wall portion formed in the arrangement direction, the second side wall portion coupling to the first side wall portion. The first side wall portion and the second side wall portion are formed so as to have the sum of lengths of the first side wall portion and the second side wall portion in the arrangement direction smaller than the thickness of the circuit body. The first case member has a deforming portion smaller than the first base plate and the second base plate in rigidity.