First feed rollers whose speed is variable, second feed rollers intermittently driven and movable in the direction of an insulated wire, a clamp which is movable in the direction of the axis of the wire and can be opened and closed during the interruption of driving by the second feed rollers, insulation cutting and stripping blades which can be opened and closed, a wire guiding device which can be opened and closed, wire cutting blades which can be opened and closed, insulation cutting and stripping blades, and a clamp which is movable along the axis of the wire and may be opened and closed during the interruption of driving by the second feed rollers in the direction of the axis of the wire, are arranged in the order mentioned from the upstream to the downstream side of the path of travel of the insulated wire, with a suitable spacing between adjacent components. The wire guiding device changes from its closed to its opened state from the time a little before a cutting blades group starts its closing operation until the time it completes its closing operation. The same also changes from its opened to its closed state from the time the clamps start their return movement until the time a little before they complete their return movement. The second feed rollers are controlled so that in the opened state of the wire guiding device, they may be moved in timed relation to the clamp on the upstream side. Thus, an efficient operation becomes possible while thoroughly disposing of the chips of insulation, and the insulated wire cut into accurate lengths can be supplied.