To provide a sheet carrying device and an image forming device for allowing efficient and safe mounting/demounting of a sheet carrying unit guided to a predetermined position without mounting/demounting a structure such as a frame on the side of a sheet carrying device body, formed to be rigid, and a component such as a stay.

In a first feeding device 10, a protruded portion 1a of each of right and left frames 1 guides the carrying unit 5 from the upstream side in a sheet carrying direction X insertably into the carrying device body 17 with sliding movement between the carrying unit 5 and an opening portion 5a formed in a unit side plate 8 provided integrally therewith, and then guides it in the upward direction of the carrying device body 17 and further guides it in a sheet cross direction Y perpendicular to the sheet carrying direction X. With the protruded portion 1a engaging with the opening portion 5a, the carrying unit 5 is guided to a predetermined mounting position without interfering with the stay 26 arranged on the carrying device body 17.