PURPOSE: To reduce the cost of a heat-resistant hollow shaft wall by forming the wall by alternately laminating the inner sections of the webs of studs, made of metallic sheets having cross sections of a Z-shape, etc., and core plates, and at the same time, fixing double-layer fire-resistant wall plates to the outside flange sections of the webs.

CONSTITUTION: A core plate 52, composed of a paper-coated gypsum wall board, etc., is placed on the web 26 of a floor track 24 and fixed to a flange 30 with screws 74. Then horizontal studs 54 and plates 52 are alternately laminated upon the plate 52, and at the same time, the end sections of the plates 52 are held in the channel 48 of a corner post 40. At holding of the end sections of the plates 52 in the channel 48, the edges 62 of the plates 52 are engaged with a plurality of tab 86 installed to the studs 54. Then double-layer broad wall plates 56 and 58 composed of gypsum wall board, etc., are fitted to the outer flanges 82 of the studs 54 and corner post 40 with screws, etc. Therefore, a wall can be constructed inexpensively from one side and a relatively inexpensive safe wall can be constructed first around a shaft hole which is formed to make a haft easily accessible for the installation of a cant, etc. In addition, the number and inventory of parts can be also reduced.