To uniformly maintain intervals of pleated parts by suspending and supporting a curtain material constituted by connecting many sheets of plates so that the plates may rotate in the vertical direction from a head box and supporting each one sheet of plates between respective wefts of ladder cords suspended from the head box.

A bottom rail 3 is formed at the lower end of a curtain material suspended and supported from a head box 1, an elevating and lowering cord 4 whose upper end part is wound and fixed on/to a winding shaft 5 which is rotatably supported within the head box 1 is passed through both the side parts of the curtain material 2 and the lower end of each elevating and lowering cord 4 is connected with the bottom rail 3. The curtain material 2 is constituted by connecting many sheets of plates 6 arranged along the vertical direction so that the plates 6 may rotate each other by a metallic connection ring 7 and each one sheet of the plates 6 is inserted and passed between respective wefts 9 of ladder cords 8 suspended on both the side parts of head box 1. By supporting the lower edge of each plate 6 by each weft 9, an inclined angle of each plate 6 is uniformized.