Abstract: A retention device for floppy disk pack is disclosed. This device comprises a substrate which is provided with respective upper and lower retention means for retaining and supporting the upper and lower ends of a floppy disk pack, respectively, in such way that the tongue portion of the upper end of floppy disk pack is just fully inserted into the upper retention means by the guidance of the opposite slant edges of a tongue portion on the upper retention means so as to receive the tongue portion on the upper retention means completely within the floppy disk pack and to leave the opening of the pack outside.