To shear a wiring pipe only by providing an inner guide member inserted between the inner surface of the wiring pipe and a wiring wired in the inside thereof with an outer guide member held to the outer peripheral surface of the wiring pipe.

An inner guide member 4 is installed below an outer guide member 2. The inner guide member 4 is inserted between the inner surface of a wiring pipe 1 and a wiring wired in the inside thereof with the outer guide member 2 held to the outer peripheral surface of the wiring pipe 1. The inner guide member is installed at a space just under an opening 8 of the outer guide member 2, and the width thereof is made smaller than that of the outer guide member 2 to be easily inserted inside the wiring pipe 1. The opening 8 of the outer guide member 2 is an elongated hole, and the width and length thereof are set to such dimensions that a rotary cutting blade of a cutter 6 can be inserted.