An electronic control device mountable on an end portion of a motor wherein, when mounted on the end portion of the motor, the electronic control device is configured to control the motor, the electronic control device comprising: a connector case (3, 3b); two or more connectors comprising a power supply connector and another connector (2a, 2b), the two or more connectors being mounted to an external side of the connector case; a control unit mounted to an inner side of the connector case; and a power supply circuit unit comprising circuit components mounted to the external side of the connector case, the power supply connector and the another connector being mounted apart from each other, the another connector being connected to the control unit by passing through the connector case not via the power supply circuit unit, the power supply circuit unit comprising power supply conducting bars (13,14,15) adjacent to each other on an inner side of the connector case, the power supply conducting bars being connected to the circuit components and the power supply connector by passing through the connector case and also being connected to the control unit, wherein the power supply circuit unit comprises the power supply conducting bars (13,14,15), the power supply conducting bars comprising a first power supply terminal (5, 6) of the power supply connector and characterized in that the power supply conducting bars (13,14,15) further comprise a second power supply terminal (8, 9, 10) to be connected to the control unit, and wherein the first power supply terminal and the second power supply terminal are arranged on an outer periphery side in the same planar region, the planar region being on the inner side of the connector case or inside the connector case, in directions roughly orthogonal to each other or roughly opposed to each other, and are arranged apart from the another connector, wherein the power supply conducting bars (13,14,15) are arranged in the same plane without overlapping. a connector case (3, 3b); two or more connectors comprising a power supply connector and another connector (2a, 2b), the two or more connectors being mounted to an external side of the connector case; a control unit mounted to an inner side of the connector case; and a power supply circuit unit comprising circuit components mounted to the external side of the connector case, the power supply connector and the another connector being mounted apart from each other, the another connector being connected to the control unit by passing through the connector case not via the power supply circuit unit, the power supply circuit unit comprising power supply conducting bars (13,14,15) adjacent to each other on an inner side of the connector case, the power supply conducting bars being connected to the circuit components and the power supply connector by passing through the connector case and also being connected to the control unit, wherein the power supply circuit unit comprises the power supply conducting bars (13,14,15), the power supply conducting bars comprising a first power supply terminal (5, 6) of the power supply connector and characterized in that the power supply conducting bars (13,14,15) further comprise a second power supply terminal (8, 9, 10) to be connected to the control unit, and wherein the first power supply terminal and the second power supply terminal are arranged on an outer periphery side in the same planar region, the planar region being on the inner side of the connector case or inside the connector case, in directions roughly orthogonal to each other or roughly opposed to each other, and are arranged apart from the another connector, wherein the power supply conducting bars (13,14,15) are arranged in the same plane without overlapping.