A pressing member (138) applies a pressing force to a trailing end of a photosensitive-member unit (21) in a direction (F) which intersects a predetermined reference direction (F1), allowing the pressing force to have both a first component (F1) in the predetermined reference direction (F1) and a second component (F2) perpendicular to the predetermined reference direction (F1). A trailing end is pressed in the predetermined reference direction (F1) by the first component. In the mounted state, the leading end is in contact with the reference member (125) at two contact surfaces including a first contact surface (113) and a second contact surface (114). The first contact surface (113) defines a first positioning direction being perpendicular to the first contact surface (113) and intersecting the predetermined reference direction (F1). The second contact surface (114) defines a second positioning direction being perpendicular to the second contact surface (114) and intersecting both the predetermined reference direction (F1) and the first positioning direction, allowing the photosensitive-member unit (21) to be positioned with respect to the main body (2).