To provide an opening building material which can reduce a level difference between a multiple glass surface and a width surface of a glass frame members framing a multiple glass, and is excellent in designability, thermal insulation and the like.

An opening building material includes: a plurality of glasses 9, 9; a spacer 8 which is disposed between the glasses 9, 9; glass frame members 11, 12, 13, 14 disposed on at least one side of the four peripheral sides of the glass 9; and an edge member 26. The spacer 8 is bonded to the inside surfaces 9c, 9c of the glasses 9, 9 with a primary seal 15. The edge member 26 has a base part 27 and an extension part 28 extending from the base part 27. The base part 27 is disposed so as to face headers 9b, 9b of the glasses 9, 9, and the extension part 28 is inserted between the glasses 9, 9. The edge member 26, the spacer 8, and the glasses 9, 9 are bonded with a secondary seal 20. The glass frame members 11, 12, 13, 14 have covering parts 40a, 40b covering the primary seal 15 and the secondary seal 20. The edge member 26 is fixed to the glass frame members 11, 12, 13, 14.