PURPOSE: To provide easy cleaning by sweeping out dust accumulated on the recessed surface of a main body side through the rotating operation of a display part, preventing the dust by a barrier from moving to a keyboard, and gathering it at a dust collection part.

CONSTITUTION: The recessed surface 5 is formed on the side of the main body 4 nearby the end surface 2 of the rotary part 1b of the display part 1, and a brush 3 is added in a belt shape at the end part of the end surface 2 on the side of a display screen 1a along its lateral width (at right angles to the paper surface). Further, a flat part 7 as the dust collection part and the adjacent barrier 8 are provided at a part which is contiguous to the keyboard 6 and crosses the recessed surface 5. When the display part 1 is rotated when opened or closed, the brush 3 slides on the recessed surface 5 to sweep out the dust accumulated on the recessed surface 5 and the dust while prevented by the barrier 8 from moving toward the keyboard 6 is gathered on the surface of the flat part 7. The dust collected on the flat part 7 and dust sticking on the top surface of the brush 3 are swept and removed by another brush at right angles to the paper surface.