<；P>；PROBLEM TO BE SOLVED: To provide a rafter roof structure of a high-strength building of a simple steel construction, while reducing construction costs. <；P>；SOLUTION: This rafter roof structure of the steel construction, which is joined onto a lower structure of steel construction, comprises: a plurality of columns 2 which are erected with a long span in a span direction and with a short span in a ridge direction； a trussed girder which is joined to upper portions of the plurality of columns erected with the long span in the span direction； and a structural valley gutter 4 which is joined to top portions of the plurality of columns erected with the short span in the ridge direction. The roof structure is constituted as a trussed structure of steel construction, which is composed of a ridge beam 5 and a rafter 6, in which the ridge beam of the roof surface serves as an upper chord, and in which the structural valley gutter of the lower structure serves as a lower chord. <；P>；COPYRIGHT: (C)2008,JPO&INPIT
