To simplify support and ventilation structures for a ridge tile on a ridge part of tile roofs while enabling the construction to be performed simply and in a short time.

An angle tile receiving part 15 and left and right side wall parts 16 that extend downward from the tile receiving part 15 are integrally provided in a rail body 12. With the bottom ends of the side wall parts 16, left and right leg members 13 are connected so as to allow angle adjustment, to form a backing rail 10 for ridge. The backing rail 10 for ridge is attached at the apex of left and right roof boards 4 so as to straddle a ventilation gap 6. A ridge tile 11 is laid and fixed on the tile receiving part 15, and a vent hole that opens into the ventilation gap 6 is formed in the side wall parts 16 or the leg members 13.