A support for receiving an HDD main body installed in an apparatus main body of an AV server. An HDD unit formed by attaching, to peripheries of the HDD main body, a frame having at least a gripping portion and a latch. The support has a plurality of slots which are formed vertically at opposing positions inside of both sides in a parallel state at regular intervals, and a latching portion at an upper edge in a lateral direction. Vents are provided between the slots, and a guide member having a groove portion is disposed in each slot. The HDD unit is inserted into a slot with the frame being guided into the groove portion of the guide member. The latch of the frame is engaged with a latching portion of the support so that each HDD unit is locked independently.