PURPOSE: To reinforce the growth of crystals by coating the surface of a porous metal support with Ni, Co or Mo in the form of metal and/or oxide, impregnating the support in a synthetic gel and depositing a zeotype material on the support.

CONSTITUTION: The porous metal support of the stainless steel or the like having an average pore diameter of 0.1 to 2000 μm is impregnated in an organic solvent and after a degreasing treatment, its surface is coated with Ni, Co or Mo in a prescribed thickness in the form of metal and/or oxide by Rf sputtering or the like. Besides, an NaAlO2 aqueous solution is added and mixed with an Na2SiO3 aqueous solution, and a hydrogel for depositing the crystalline zeo-type material is adjusted. Next, the surface coated porous metal support is impregnated in the hydrogel and left while heating and after the zeo-type material is deposited on the support, the support is taken out, washed and dried. After the process for impregnation in the hydrogel, crystallization, following washing and drying is repeated again more than twice and a filter coated with the crystal membrane of the zeo-type material having the prescribed thickness is provided.