A mounting apparatus is provided for securing a data storage device. The data storage device has two opposite side walls. Each side wall forms a pair of posts. The mounting apparatus includes a chassis, a bracket mounted in the chassis for accommodating the data storage device, and a latch member pivotally mounted to the bracket. A plurality of slots is defined in one side wall of the bracket for receiving the posts of the data storage device. The latch member includes a base. An elastic arm and a hook extend from the base. The elastic arm resists against the chassis to urge the hook partially covering one of the mounting slots for preventing a corresponding post received in the mounting slot disengaging therefrom. The latch member is being pressable to depress the elastic arm and remove the hook away from the mounting slot thereby release the corresponding post.