A loading/ejecting device for loading and ejecting a floppy disk into and from a magnetic disk drive apparatus has a holder for containing the disk therein. The holder is supported by a pair of guide plates to be movable directly between a first position where the disk can be inserted into or ejected from the holder and a second position where the disk can be reproduced or recorded. A loading/ejecting member is supported by the guide plates to be movable between an initial position and a forward position. The member is urged by tension springs toward the forward position and is latch by a latching member in the initial position. When the disk is inserted into the holder, a urging member supported on the holder is moved by the disk to push the latching member, thereby disengaging the latching member from the loading/ejecting member. As a result, the loading/ejecting member is moved from the initial position to the forward position, thereby moving the holder from the first position to the second position. A hold plate is mounted on the holder and locks the disk in a predetermined position in the holder when the disk is inserted into the holder. The loading/ejecting member has an urging arm. When the loading/ejecting member is moved from the forward position to the initial position, the holder is moved from the second position to the first position by the member and the hold plate is urged by the urging arm to release the locked state of the disk.