To provide a screen device that expands an allowable range corresponding to the size of an installation area such as an opening of a building.

First and second storages 15 and 16 for individually housing two slide guide frames 9 are arranged in different positions inside screen mounting frames 2 and 3, respectively; and the two slide guide frames are connected to each other at each free end housed in the same screen mounting frame, by means of a tension member 21 forming an uncrossed loop 20.