To provide a vertical louver device which makes possible an adjustment to the amount of incoming light and the volume of incoming air by freely rotating a louver after the louver has been extended, and which can be stored by being contracted and folded when it is not used.

A movable box body is provided on the up-and-down guide rails which have been provided in parallel with each other, and one unit is formed by attaching the louver to a rotary axis which is carried out from the movable box and has an angle-change means. Then a plurality of these units are provided on the up-and-down guide rails and move on the rails one by one. Thus, at the time of full extension, the plurality of units line up in order, and each of the louvers can be adjusted simultaneously with flexible opening-and-closing angle. When the vertical louver device is not necessary, each of the units can be converged on one side and stored by making the louvers opened at a full angle.