A recording medium accommodating case includes a main body, a lid and a joint portion. The main body is formed with a disk storage area and a cartridge storage area. On the lid, a booklet storage area is formed. The disk storage area includes a protrusion engaged in a center hole of a disk, a supporting portion which is brought into contact with a rear surface of the disk to support the disk, and a disk fall preventive portion which is formed in an outwardly projecting manner from an upper side surface of the protrusion and engaged in the center hole of the disk. The cartridge storage area includes a cartridge holding portion which comes into contact with a side surface of a cartridge to hold the cartridge, and a cartridge fall preventive portion which is formed in an inwardly projecting manner toward an inner surface of the cartridge holding portion. On the booklet storage area, a booklet holding portion having a space to store and hold a booklet in a direction of the thickness of the lid and faced to the disk storage area is formed. In addition, when the main body and the lid are closed, the booklet storage area faces the disk surface thus preventing the disk from falling.