A screen device (1; 23) comprising: a screen which allows free contraction and expansion and is mounted between a pair of slidable screen mounting frames (2, 3) arranged on the left and right sides so as to oppose to each other; slide guide frames disposed respectively near both upper and lower end portions of the screen, the slide guide frames having flexibility, having free ends at both ends thereof, and being capable of being contained in and drawn out from the screen mounting frames; and the slide guide frames keeping their straightness at drawn out portions thereof when being drawn out from the screen mounting frames in association with the sliding movements of the screen mounting frames; characterized in that: a first housing section and a second housing section, configured to contain the two slide guide frames individually, are partitioned and disposed respectively in the interior of each screen mounting frame; the first housing section and the second housing section are arranged at different positions in the width direction in the interior of the screen mounting frame and extend in the direction of the height of the screen mounting frames; and the two slide guide frames are connected to each other at the respective free ends contained in the same screen mounting frames by tension members, the tension members being capable of transmitting tension and each forming a loop having no crossing point. a screen which allows free contraction and expansion and is mounted between a pair of slidable screen mounting frames (2, 3) arranged on the left and right sides so as to oppose to each other; slide guide frames disposed respectively near both upper and lower end portions of the screen, the slide guide frames having flexibility, having free ends at both ends thereof, and being capable of being contained in and drawn out from the screen mounting frames; and the slide guide frames keeping their straightness at drawn out portions thereof when being drawn out from the screen mounting frames in association with the sliding movements of the screen mounting frames; having flexibility, having free ends at both ends thereof, and being capable of being contained in and drawn out from the screen mounting frames; and the slide guide frames keeping their straightness at drawn out portions thereof when being drawn out from the screen mounting frames in association with the sliding movements of the screen mounting frames; characterized in that: a first housing section and a second housing section, configured to contain the two slide guide frames individually, are partitioned and disposed respectively in the interior of each screen mounting frame; the first housing section and the second housing section are arranged at different positions in the width direction in the interior of the screen mounting frame and extend in the direction of the height of the screen mounting frames; and the two slide guide frames are connected to each other at the respective free ends contained in the same screen mounting frames by tension members, the tension members being capable of transmitting tension and each forming a loop having no crossing point. a first housing section and a second housing section, configured to contain the two slide guide frames individually, are partitioned and disposed respectively in the interior of each screen mounting frame; the first housing section and the second housing section are arranged at different positions in the width direction in the interior of the screen mounting frame and extend in the direction of the height of the screen mounting frames; and the two slide guide frames are connected to each other at the respective free ends contained in the same screen mounting frames by tension members, the tension members being capable of transmitting tension and each forming a loop having no crossing point.