A cartridge holder is shown which comprises a back portion which has at an inner surface a plurality of cartridge gripping parts by which one sides of cartridges are gripped, a pair of lid portions which are pivotally connected to opposed sides of the back portion through respective major hinge portions; catching and caught portions which are provided at free ends of the lid portions and lock the lid portions when the lid portions are pivoted toward their closed position; and a plurality of extra hinge portions which are defined by the back portion. By roundly flexing the back portion at the major hinge portions, the cartridge gripping parts, that is, the cartridges gripped by these cartridge gripping parts are opened like a fan. Thus, upper ends of the cartridges are separated thereby facilitating handling of the upper ends of the cartridges by the fingers of a user. In order to prevent a swell-out phenomenon of the back portion which would occur when the back portion is roundly flexed, there is provided a swell-out phenomenon suppressing means. In order to prevent removal of the cartridges from the cartridge gripping parts which would occur when vibration and shock are applied thereto under conveying of the holder, there is provided a cartridge retaining rib.