PURPOSE: To obtain a woody cement board having high moisture absorbing property, humidity controlling property, sound absorbing capacity, high strength, etc., and deodorizing function by mixing and kneading a specified ceramic powder having a function for adsorbing and catalytically oxidizing low molecular weight gas in a stage of blending wood fibers with cement.

CONSTITUTION: Ceramic powder having a function for adsorbing and catalytically oxidizing a low molecular weight gas which has been produced by acting electromagnetic wave or ozone on a fine porous material and oxidizing produced product is mixed directly with the wood fiber and cement, or into a mixer contg. the wood fiber and the cement, and the mixture is kneaded, in a stage of blending wood fibers with cement during a process for producing woody cement board. When ceramic powder consisting of a reactive ceramic agent such as silicate, zirconate and a filler such as zeolite is used as the ceramic powder, better deodorizing effect may be attained.