To facilitate setting of a crest level and fix an erection support on a metal fitting for building by using a crest-cum-insert metal fitting formed with a bolt part, a crest point fixed at the head of the bolt part, and a mounting part for mounting the metal fitting for building at the crest point.

The bolt part 11 of a crest-cum-insert metal fitting 10 is screwed in the placing insert 1 of a semi PC floor board, and tightened and fixed with a tightening nut 14. The height of a crest level L1 is adjusted according to the screwing amount of the crest-cum-insert metal fitting 10, so that the crest level L1 of site placing concrete slab can be set easily by the top end part at the crest point 12 fixed at the head of the bolt part 11. Erection of a PC wall board is carried out by fixing a support on the hook part of erection metal fitting fitted on the mounting part 13 at the crest point 12 of the crest- cum-insert metal fitting 10 embedded in the slab 21, and the hook of the erection metal fitting fitted on the PC wall board. It is thus possible to use it for the crest level L1 and erection.