A main body to be moved and operated along a workpiece includes a joining roller which elastically presses the supplied adhesive tape against a tape joining face of the workpiece, guide members which determine the position of the main body and maintain the posture of the main body with respect to the workpiece being engaged with the outer face of the workpiece at the opposite side of the tape joining face, a separator guide which is arranged to be opposed to a tape supply roller, and a tape guide which is arranged in the vicinity of the side where the adhesive tape is reeled out toward the separator guide. On the separator guide, a separator guide face is formed, which guides a separator st separated from the adhesive tape into a direction different from an adhesive tape joining direction.