A cellular phone capable of observing a background. The cellular phone includes a first main body and a second main body slidably connected to the first main body. A display is provided to the second main body. The display is divided into a first area that is not overlapped with the first main body when the second main body is slidably open, and a second area that is overlapped with the first main body when the second main body is slidably open. In the cellular phone, the first area has first pixels formed into a transparent structure in which a background is observed, and the second area has second pixels formed into a non-transparent structure in which the background is not observed.