An electric cable guiding device includes a fixed guide block and a movable guide block. A projected round surface is formed in the fixed guide block, and an indented round surface is formed in the movable guide block. In addition, a groove is formed in the indented round surface. At the time of guiding an electric cable, the movable guide block is fitted in the fixed guide block. In this state, the indented round surface and the groove constitute an electric cable guide path. The electric cable is fed into the electric cable guide path by rollers. Consequently, the electric cable is guided in a U shape along the electric cable guide path. The front end of the electric cable drawn out of the electric cable guide path is clamped. Thereafter, the movable guide block is moved to an electric cable measuring position that is spaced apart from the fixed guide block by a predetermined distance. In this state, the electric cable is fed by a required length. The rear end of the electric cable is clamped by a guide clamp and then is cut.