A mounting apparatus for attaching a data storage device to a chassis includes a latching member, first and second elastic members and a button. The latching member defines a through hole therein and forms a latching pin at a first end thereof. The button includes an abutting portion and a pressing portion extending up from the abutting portion. When the mounting apparatus is mounted to the chassis, the button is placed on a bottom side of the latching member, the latching member is movably mounted to the chassis, the first elastic member is compressed between the second end of the latching member and a baffle formed on the chassis, the second elastic member is compressed between the button and the chassis, the pressing portion of the button extends through the through hole and extending out of a top surface of the latching member.