A power semiconductor module comprising a housing of a first plastic, at least one substrate carrier with a circuit constructed thereon and electric terminating elements extending therefrom. The housing includes attachment means for its permanent connection with the substrate carrier. The housing has a permanently elastic sealing device of a second plastic which is formed integrally with the housing and encircles and is directed towards a first inner main surface of the substrate carrier. A method for constructing such a module includes the steps of constructing a housing of a first mechanically stable plastic and a sealing device of a second permanently elastic plastic; disposing the at least one substrate carrier on the housing; and permanently connecting the housing to the substrate carrier.