A powder carrier screw includes a rotation shaft which is provided along a path which carries powder such as toner and is rotatably supported by a container forming the path, the rotation shaft having one end from which a rotation driving force is applied, a coil which is provided in a spiral form along an outer circumference of the rotation axis, the coil having a shaft center of the rotation shaft as a shaft center and having both end portions joined to both end portions of the rotation shaft, and the coil rotating along the rotation of the rotation shaft, a thick portion which is provided in at least one end portion of the coil, the thick portion having a thickness larger than a thickness of a general portion of the coil, and a coil welded portion in which the thick portion and the rotation shaft are welded.