A cartridge storage container used in combination with another cartridge storage container identical in configuration with the cartridge storage container to provide a closed or interlocked cartridge storage container for storing a plurality of flat tape cartridges when the two cartridge storage containers are disposed in an inverse, confronting orientation and joined together. The cartridge storage container has at least one storage compartment so configured that a plurality of tape cartridges are stored therein in two way, individually in bulk and collectively in one bundle. The cartridge storage container is provided with a moisture absorbent in the form of sticks installed in shock-absorbable hollow buffer ribs formed in a wall portion of the storage compartment.