A sliding mechanism is provided to couple slidably a first housing having on its surface a vertically long liquid crystal display part long in the vertical direction to a second housing having on its surface an operating part. This slide mechanism includes a rail part which is mounted on the surface of the second housing in a manner of extending in the vertical direction and is configured such that when the first housing has slidingly moved by means of the slide mechanism to the upper end side of the second housing, the operating part of the second housing will appear. Further, by means of the cam mechanism (support mechanism), the first housing is supported relative to the second housing in a switchable manner between the vertically long state and the horizontally long state.