To reduce cost and improve sound-insulating properties, to lighten weight and facilitate handling, and to enhance durability by integrally installing a sound-absorbing material having cellular structure mainly comprising concrete and being constituted by mixing synthetic-resin fibers at a specified rate on one surface of a concrete board.

The sound-insulating board is configured by sticking a sound- absorbing material 2 on one surface side of a concrete board 1 with adhesives, etc. The concrete board 1 manufactured by portland cement, sand, water, etc., is used. The sound-absorbing material 2 mainly comprising concrete and having cellular structure having open cells and closed cells on an external surface and on the inside is employed, and manufactured by mixing alkyloxy polyethylenoxyethanol with the kneaded material of portland cement and water and mixing synthetic-resin fibers formed of 100% genuine polypropylene into concrete. Accordingly, the sound-absorbing material 2 is lightened while the strength of cured concrete can be increased.