PURPOSE: To provide a bedding plate with sound absorbing property, heat insulating property and ventilating property by providing a foaming layer in a recessed part between reinforcing projections of the back surface of a cement solidified plate having a ventilation groove in the surface thereof, and forming an irregular part on the surface thereof.

CONSTITUTION: A cement solidified plate 11 having a ventilation groove 110 in the surface 111 and having plural reinforcing projections 12 in the back surface 112 is provided. In the back surface 112, the foaming raw liquid 139 composed of synthetic resin is supplied to a recessed part 121 formed between the reinforcing grooves 12, and foamed. At this stage, a molding die 93 having the irregular surface 930 is used for pushing, and the surface of the foaming layer 13 is formed with an irregular part 130 in a circle at 1-10mm of the longer diameter or in a polygonal shape. This bedding material 1 is fixed to a structural material so that the surface 111 having the ventilation groove 110 is arranged outside and that the structural material and the reinforcing projections 12 cross each other. Ventilation of the air around the bedding material 1 is therefore improved, and the generation of moisture condensation is prevented.