An electronic device includes a chassis, a rail module and an electronic module. The rail module includes a rail, first and second sliding elements. The rail disposed in the chassis has a locking slot. The first sliding element slidably disposed on the rail has an elastic piece. The elastic piece has a locking hook facing the rail. The second sliding element slidably disposed on the first sliding element and fixed to the electronic module is suitable of sliding along a path relatively to the first sliding element. The locking hook leaning against the rail is located on the path. The locking hook is suitable of being pushed by the second sliding element to be buckled to the locking slot and moves away from the path. Then, the second sliding element crosses the elastic piece for sliding along the first sliding element, and the electronic module moves out from the chassis.