A portable terminal device is provided which can improve the interest, functionality and additional value by display even when the two display modules are in the state of being overlapped. The portable terminal device includes a first unit which has a first display module, and is configured such that a user is allowed to see a side of the first unit opposite to a user's side through the first display module, a second unit which has a second display module, and a switching module and which is operable to switch the portable terminal device between a first configuration that the first unit covers the second display module, and a second configuration that the first unit is moved from the first configuration with respect to the second display module so that at least a part of the second display module is exposed to an outside.