as a pbt poly butylene terephthalate resin a nylon resin or any other resin capable of serving the principles of the present invention when mounted to a vehicle the circuit unit 2 is positioned toward the rear of vehicle relative to the bushing 3 the flange portions 3 b 3 c of the bushing 3 protrude toward the front side of the vehicle beyond a front surface 4 a of the resin case 4 therefore because collisions are expected to occur on the front side of the vehicle according to the electrical circuit device 1 the flange portions 3 b 3 c of the bushing 3 protrude toward a collision prone side of the vehicle to serve as a collision protection rigid body the effect of the structure of the above described electrical circuit device 1 during a collision is now described as stated above the electrical circuit device 1 is fixed to a designated surface of a vehicle by fastening the threaded portion 5 a of the bolt 5 through the through hole 3 a of the bushing 3 because the flange portions 3 b 3 c of the bushing 3 which are disposed on the front side of the electrical circuit device 1 protrude toward the front.