PURPOSE: To enable the free selection of the gear position for driving without providing a transporting path with a through-hole as a gear bearing by supporting a hollow transporting path member having projecting or recessed lines formed at a prescribed angle with the axial center on its inside wall turnably around the axial center.

CONSTITUTION: This waste toner transporting device 36 is formed to a hollow pipe shape and is internally provided with the spiral projecting lines 38. A gear 40 for turning the waste toner transporting device 36 around its longitudinal axis is provided in the outer periphery and turns the waste toner transporting device 36 by receiving the rotating force from a power transmission gear. The waste toner transporting device 36 is supported turnably by a supporting member 41. The gear 40 for driving may be provided at any point of the hollow pipe and, therefore, the disposition of the sliding parts of a toner pool 33 and the waste toner transporting device apart from the gear 40 is possible. Then, the intrusion of spilled toners between the gear 40 and the power transmission gear is prevented.