To prevent a displayed image on a display unit viewed from a user from varying when the user operates a dial key etc in a portable information processing unit equipped with a main body and the display unit.

A portable telephone is equipped with a main body unit 10 provided with an operating surface 10a on which a transmitting unit 30, a dial key 32, a visible image positioning switch 36, etc are arranged and a display unit 20 which is located at the one end of the main body 10, set turnable around a first axis S1 along the operating surface 10a, and provided with a display plane 20a on which a receiving unit 38 and a display 40 are arranged. The portable telephone is turned from a closed state to an opened state, and when the visible image positioning switch 36 is pushed down, the volumes of rotational displacements induced in the main body unit 10 around a first axis S1 and a second axis S2 are estimated resting on angular velocities acquired from a first and a second gyroscopic sensor, and the display unit 20 is turned around the first axis S1 and the second axis S2 in the directions opposite to the rotating directions induced in the main body unit 10 by the volumes of the estimated rotational displacements.