Abstract: The invention presents a new way to implement bigger keyboard in basic mobile terminal devices without increasing the size. The mobile terminal device is foldable, and can be arranged in two different closed positions. A mobile terminal device according to the invention comprises a housing, at least two covers pivotably attached to said housing, and at least two different operative surfaces. The two covers are movable between at least two closed positions. The at least two different operative surfaces are arranged on different surfaces of one of the housing and/or the covers in a way that in at least one of the closed positions, one of the two different operative surfaces is located on an outer surface of the mobile terminal device in the closed position. So a user can chose which user interface is presented to him by closing the mobile terminal device in one way or the other.