First and second elongated support members for supporting a circuit board and for transporting the circuit board in one direction parallel to the lengthwise direction of the support members are provided on a frame, and a blade member is rotatably supported on the frame for rotation about its own axis in a plane parallel to the plane of the circuit board. While the circuit board is being transported with opposed edges of the circuit board guided along the support member, the blade member trims excessive length from wires extending from the circuit board.