A photosensitive drum is axially rotatable and has a surface on which an electrostatic latent image is formed. A developing device includes a development roller spaced from the photosensitive drum. The development roller includes a cylindrical sleeve and a coating layer, and the photosensitive drum includes a cylindrical tube and a functional layer. Each of the coating layer and functional layer is formed by dipping the sleeve or tube into a dipping bath with the sleeve or tube directed axially vertically. An axial end portion of the development roller that is lower during the dipping process is disposed opposite to an axial end portion of the photosensitive drum that is higher during the dipping process, and an axial end portion of the development roller that is higher during the dipping process is disposed opposite to an axial end portion of the photosensitive drum that is lower during the dipping process.