An image-forming device includes a main body and a tandem photosensitive-member unit. The tandem photosensitive-member unit includes a unit frame, a plurality of photosensitive members, a front-side grip part, and a rear-side grip. The unit frame is configured to be slidably installed to and removed from the main body in a predetermined direction. The unit frame has a leading side and a trailing side with respect to the predetermined direction. The plurality of photosensitive members is provided corresponding to a plurality of colors and is supported by the unit frame. The front-side grip part is provided at the leading side of the unit frame. The rear-side grip part is provided at the trailing side of the unit frame.