Abstract: In a structure for assembling a housing and a connector in which a connector is inserted into a housing, and a fitting surface of the connector adapted to be connected to a mating connector and oriented in a direction perpendicular to an inserting direction projects outside the housing through an opening formed in the housing, an inclined wall which is inclined with respect to the inserting direction of the connector is provided on an inner surface of the housing, an annular inclined flange which opposes to the inclined wall is provided on an outer peripheral side of the fitting surface of the connector, a seal member is interposed between the inclined wall and the inclined flange, the seal member is pressed between the inclined wall and the inclined flange by fixing a substrate provided with the connector to the housing.