A protection layer (1d) having a volume resistivity of 10<sp>10</sp>Ω·cm to 10<sp>17</sp>Ω·cm is laminated on the surfaces of insulation layers (1b), (1c) in a carrying member (1) so that a sum of layer thicknesses of the insulation layers (1b), (1c) and the protection layer is smaller than the interval between traveling wave generation electrodes (2). Accordingly, a traveling wave electric field generated by electrodes (2) is positively exposed to the surface of the carrying member (1), and the surface voltage of the member (1) will not vary even on contact with a developer (T), whereby it is possible to prevent the developer (T) from sticking on the surface of the member (1) and positively and constantly carry the developer (T) to a developing position.
