In an ink ribbon cassette, a case housing an ink ribbon wound around a supply-side bobbin and the ink ribbon wound around a wind-up side bobbin includes a case main body including a cylindrical supply-side case portion to house the ink ribbon wound around the supply-side bobbin and a cylindrical wind-up side case portion to house the ink ribbon wound around the wind-up side bobbin and a cover to close one end of the cylindrically formed supply-side case portion and one end of the cylindrically formed wind-up side case portion. The cover is removably attached to the case main body.