PURPOSE: To make it possible to cover a vacant part of a cable intake hole without any gap in conformity with the shape of connection cable by laying out a plurality of short strips having electric or electromagnetic shielding effect with one, end bend, which are installed in parallel to an opening and cover the entire opening, in one layer face to face, movable freely respectively and fixing them with a movable bar at any arbitrary position.

CONSTITUTION: Short strips 6 which have electric or electromagnetic effect are placed face to face in one layer and are inserted into stoppers 51. When a bend end 61 comes into contact with the end face of a movable bar 5, a cable intake port is full open. A vacant part inside the opening can be inhibited so that it may not exceed the width of the strips 6 if an attempt is made to introduce a connection cable 9 under the state indicated by 2, transfer the movable bar 5 up to the position in close proximity with the outside shape of the connection cable 9, fix the bar, pull out the strips 6 respectively and knock the bent end 61 at the tip against the connection cable 9 being led in or the opposite side of the opening and fixing them at that position. Therefore, if the width is further reduced, it will be possible to minimize the gap accordingly.