Mount for recording media and recording media library apparatus using the mount

A recording media library apparatus comprising:

• a mount for supporting thereon a recording medium, said mount having at least one end surface oriented in a predetermined horizontal transfer direction thereof, said one end surface being slanted with respect to a direction normal to the horizontal transfer direction;
• a storage section that stores therein a plurality of said mounts each supporting the recording medium;
• a medium drive unit that reads and/or write data on the recording medium;
• and
• a transportation mechanism that carries said mount between said storage section and said medium drive unit and performs a predetermined handling operation to pass, in the horizontal transfer direction, said mount to or from said storage section or said medium drive unit.