An ink ribbon cartridge to be inserted to and removed from a printer device that prints an image to a printing medium by heating the printing medium with an ink ribbon closely attached thereto. The ink ribbon cartridge includes: a cartridge body provided with a pair of housing sections for housing, with a space therebetween, a pair of spools to be able to freely rotate for winding of the ink ribbon; and a pair of guide sections that are provided on both side surfaces in a direction orthogonal to an insertion/removal direction of the cartridge body, and serving as a guide for insertion to and removal from an ink ribbon cartridge holder provided to the printer device through support by a guide support section formed to the ink ribbon cartridge holder with a cross section of a substantially square bracket shape.