PURPOSE: To surely provide a synchronous rotation by installing each one end of several blades to a first frame material, adjustably installing the other end to a second frame material, and holding intermediate blades in such a state as freely rotating about a longitudinal shaft by a support tension of a fixing tool.

CONSTITUTION: A louver screen 2 is provided with an upper frame part 4 covered with a cover member 6, a lower frame material 8 covered with a cover member 10, a lateral frame material 12 covered with a lateral cover member 14, and a plurality of blades 16 arranged in parallel to each other. A control rod 20 is provided one end or the both ends of a screen device and attached to the frame material rotatably about a shaft center and respective ends of cross wires 24 are fixed to the tips of tabs 22 provided to the rod 20 spaced at constant intervals. The respective cross wires 24 are connected to the all of the blades 16 so that the screen is opened/closed by the simultaneous rotational movement of the blades 16 following to the movement of the control rod 20. By this constitution, the blades can firmly be fixed.