A handheld electronic device includes a display body, an input body and at least a track. The input body and the display body are overlapped with each other. The track is disposed between the display body and the input body, wherein the extending direction of the track is substantially neither perpendicular to nor parallel to the longitudinal direction or the traverse direction of the display body or the input body, and the track enables the display body to switch between at a first position and at a second position relative to the input body. The traverse direction of the display body is substantially parallel to the traverse direction of the input body when the input body is at the first position, and the longitudinal direction of the display body is substantially parallel to the longitudinal direction of the input body when the input body is at the second position.