To provide an attic space parting wall which functions as a structure to support weight of a roof while functioning as a wall.

An attic space parting wall 1 is composed of a plurality of triangular or quadrangular frame part members 2, 3, and 4, which provide a slanted frame part with a slant corresponding to a slope of a roof, a horizontal frame part and a vertical frame part, arranged as forming the slope of the roof. Adjacent frame part members (2, 3)(3, 4)(4, 4) are connected with purlin receiving components 20 and 30. A wall surface material (such as a gypsum board) is attached on the frame part members 2, 3, and 4.