A paper separating device for separating a paper sheet includes a frame member, an image carrier, a securing plate, and two types of assemblies. The two types of assemblies include: a first assembly that includes a separation claw configured to separate the paper sheet from the image carrier, a guiding member configured to guide the paper sheet, and a holder with an engaging portion; and a second assembly that engages the guiding member alone to the holder with the engaging portion without holding the separation claw. The frame member and the securing plate each include an assembly securing portion with an engaged portion to be engaged with the engaging portion of the holder. One of the two types of assemblies is secured to the assembly securing portion disposed at the securing plate while another is secured to the assembly securing portion disposed at the frame member.