This sheet separating device 50 includes: a release member 51 provided facing a rotating member (such as a fixing belt 43) arranged on a sheet transport path, and which extends toward the surface of the rotating member; a support member 54 that supports both ends of the release member 51; and a separating tip portion 71 arranged between the release member 51 and the rotating member. The separating tip portion 71 is provided so as to make contact with the rotating member, and is swingably attached to the support member 54.