To provide a shielding device in which the upper and lower parts of the frame section of a frame are allowed to open and the vertical intermediate part thereof is allowed to close.

An upper shield body (upper louver blade 2-1), an intermediate shield body (intermediate louver blade 2-2), and a lower shield body (lower louver blade 2-3) are so attached to the upper part of the frame 1, the vertical intermediate part of the frame, and the lower part of the frame, respectively as to be rotatable between a closed attitude and an open attitude. The shielding device also includes an operation part for independently rotating the lower shield body and the intermediate shield body.