PURPOSE: To provide a resin filled type electronic circuit device in which a connector and a case are mutually fastened firmly, the rigidity of the case is increased, and further the easiness of resin filling workability is equal to or more than that of a conventional one.

CONSTITUTION: A resin filled type electronic circuit device is composed of an electronic parts-mounted circuit board 2, a connector 3 provided on the circuit board 2, a top face open case 1 containing the circuit board 2, and resin 6 filled and cured in the case 1. The fitting portion 10 of the connector 3 formed in the side wall of the case 1 is formed into cylindrical. The periphery of the connector 3 is held by the case 1 in a state that the connector 3 is fitted into the cylindrical fitting portion 10 from the side thereof.