In-vehicle device controller

An in-vehicle device controller (22a, 22b, 23) controlling an in-vehicle device (22A, 22B, 12) for operating a high-voltage source (11A) installed in a vehicle includes stopping means (22a4, 22b4, 23D) stopping control or operation of the in-vehicle device (22A, 22B, 12) to stop the operation of the high-voltage source (11A) when an open/close sensor (18a, 18b) detects opening of an openable member of the vehicle.