Abstract: A construction method includes a charcoal paint application step in which a charcoal paint is applied to at least one of a floor, a wall, and a ceiling within a construction target room; an arrangement step in which flooring members made of Obi-sugi are arranged on the floor of the room; a diatomaceous earth application step in which diatomaceous earth is applied to the wall of the room; and a spraying step in which an antioxidant aqueous solution is sprayed on at least one of the floor on which the flooring members are arranged, the wall to which the diatomaceous earth is applied and the ceiling to which the charcoal paint is applied.