PURPOSE: To improve the appearance and the durability of a wire, simplify the structure, and facilitate the wiring work.

CONSTITUTION: At least a moving frame 3 is suspended between both side frames 2a, 2b of a square frame body 2, and a foldable bellows-like shielding body 4 openably shielding the opening region H of the frame body 2 is suspended between the moving frame 3 and one end frame 2d or between both moving frames 3, 3. A wire 5 is arranged to hold the moving frame 3 movably in parallel and holding the shielding body 4, and a groove section 6 is formed along the side frames 2a, 2b to allow the wire 5 to pass. Guide sections 8, 9 arranging the wire 5 on the depth side of the groove section 6 from the end section of the moving frame 3 to the end section of the end frame 2c in sequence are provided at the end section of the moving frame 3 and the end frame 2c or the end section of the side frame.