A handheld electronic device includes a first body, a second body stacked with the first body, a first plate between the first and second body and fixed to the first body, a second plate between the first plate and second body and fixed to the second body, a first locating structure, and a second locating structure. The first plate includes a sliding slot and a rib transversely disposed in the sliding slot and extended along the sliding slot. An edge of the second plate includes a sliding block clamped on the rib, so the second plate can move along the sliding slot. The first locating structure is disposed on the first plate and located on a moving path of the second plate. The second locating member is disposed on the sliding block, and adapted to interfere with the first locating structure on a locking position of the moving path.