PROBLEM TO BE SOLVED: To provide a composite high in safety which can effectively adsorb and absorb harmful chemical substances in the environment without easily re-emission, and to provide a production method thereof.SOLUTION: A porous composite has macro-pores of pore diameters of 50 nm or greater, determined by measurement of a pore diameter distribution with the mercury press-in method and contains, in the macro-pores, an ingredient which reacts with a chemical substance to adsorb and absorb the chemical substance within the macro-pores. The reaction with the chemical substance is preferably a neutralization reaction or a chemical reaction, and the material having the ingredient is preferably a hydraulic lime. The porous composite is obtained by preparing a composite composition comprising a material having the ingredient which reacts with a chemical substance to adsorb and absorb the chemical substance within the macro-pore, aggregate and an aqueous solvent, and then forming the porous composite by using one or more means selected from application means of applying the composite composition onto an object and hardening, casting means of casting the composite composition on the object, blowing means of blowing the composite composition on the object and roller means of applying the composite composition onto the object with a roller.
