To provide a method for simplifying the installing operation of an internal reinforced structure of a ridge having earthquake resistance even by a conventional construction method using roofing soil.

In a metal fitting for fixing plain ridge tile, a plurality of reception metal fittings 2 and 2a are arrayed in a vertical direction, and at least the lower edge site of a support bar in a reception metal fitting above the lowermost stage is constituted as a bolt part, and fixing means to a roof substrate W side is disposed at the lower edge site of the support bar in the reception metal fitting at the lowermost stage. As for the reception metal fittings, the bolt part of the support bar in reception metal fitting 2a, 2b at an upper stage is screwed into a vertically long nut in the reception metal fitting at a lower stage, and the side plates of washers in all the reception metal fittings are connected so as to be aligned. The plurality of metal fittings for fixing plain ridge tile are arrayed by every interval at a plurality of parts, and a high and horizontally long plain ridge tile fixing material 21 is inserted into a gap between the side plate of the washer in the reception metal fitting below the uppermost stage of the metal fitting for fixing plain ridge tile and the support bar in the reception fitting metal just above so as to be bridged across at least adjacent two metal fittings for fixing plain ridge tile. Thus, it is possible to simplify the installing operation.