PURPOSE: To provide a recording device which can eliminate an error in the mounting of a single pass ink ribbon.

CONSTITUTION: A pair of recessed parts are formed each in a lateral frame attached to a main case system and a cassette retaining tool is firmly introduced into each recessed part. In addition, a regulating pin is installed upright between the pair of recessed parts on the lateral frame, in such a manner that the pin leans to one recessed part side. Further, regulating recessed parts 33a, 33b which become engaged with the regulating pin, are provided on a feed roll side and a winding roll side respectively, on a cassette 17b for a multipass ink ribbon, so that the cassette 17b is prevented from reversing. A cassette for a single-pass ink ribbon has the regulating recessed part 33a which engages with the regulating pin provided only on the winding roll side. Thus a direction in which the cassette for a single-pass ink ribbon is mounted, is regulated.