Sunshade device

A sunshade device (1A) includes a pair of shade guide rails (2) across an indoor opening (R2); a shade of which opposite side edges are guided by the shade guide rails (2); and a winding shaft (5) rolling up the shade, wherein the opposite side edges of the shade are guided by the shade guide rails (2) with the side edges being folded after a folding stroke whose folded width is gradually increased toward a front end of the shade when the shade (3) is drawn out from the winding shaft (5), each of the opposite side edges of the shade is provided with a folded introduction part formed by folding a side edge portion (3a) of the shade (3) and connecting the folded side edge portion (3a) to a main body portion of the shade (3), and the folded introduction part is formed in a predetermined length from the front end of the shade (3) in an open/close direction of the shade (3).