To provide the manufacturing method of a building material for an interior wall in which various functions such as antifungal properties, deodorizing properties or the like are imparted without using chemicals having an effect on a human body for maintaining wood, and to recycle a used porous inorganic substance for resources.

The chemicals having at least one performance in deodorizing properties, antifungal properties and fungiproofness are fixed onto an inorganic raw material containing the porous inorganic substance composed of zeolite or diatomaceous earth and an inorganic binder singly or in the plural, water is added and the whole is kneaded, pressure-compressed and molded in a sheet shape and dried.