A first wrist element is provided at a distal end of a front arm of an arc welding robot rotatably about a first axial line, a second wrist element is provided on the first wrist element rotatably about a second axial line, and a welding torch is supported on the second wrist element about a third axial line. A slide mechanism which can reciprocate in a direction approximately parallel to the first axial line is provided at a proper position from an upper portion of the front arm to an upper portion of the first wrist element and a wire feeding apparatus is mounted on the slide mechanism. By sliding the position of the wire feeding apparatus in response to the attitude of the welding torch, an extending state of the torch cable can be maintained properly.