Provided is a building board having non-flammability and being excellent in designability. In the building board, an impregnated coating film, an aqueous coating film, a solvent-based clear coating film and a top clear coating film are formed, in this order, on a surface of a base member. The aqueous coating film is formed of a synthetic resin and a fireproofing agent; the top clear coating film is formed of a UV-curable type resin and a fireproofing agent; the amount of fireproofing agent in the aqueous coating film is 10 to 50 wt % with respect to the solids of the aqueous coating film; the amount of the fireproofing agent in the top clear coating film is 5 to 20 wt % with respect to the solids of top clear coating film; and the total calorific value measured in accordance with ISO 5660, for 20 minutes using a cone calorimeter, is smaller than 8 MJ/m2.