A method of manufacturing crystalline microporous material suitable for manufacturing a variety of crystalline microporous material under mild reaction conditions and under safe working environmental conditions by using simple installation. The crystalline microporous materials obtained by the present invention may be used as adsorbent agent, catalyst or separating material. According to the characterizing features of the manufacturing method of the present invention, there are provided a method of using cation compound or amine as crystallizing modifier and using, in combination, raw material including kanemite or silicon dioxide and a further method using raw material including silicon dioxide and aluminum salt. The method includes a step of mixing these components, a solid-liquid separating step for separating produced fine particles, and a crystallizing step for crystallizing the separated solid component. The invention achieves improvement in safety, economy and so on, in comparison with the coventionally practiced hydrothermal synthesis method which requires severe reaction conditions of high-temperature, high-pressure and strong alkaline. Further, the method allows freedom in adjustment of the pore diameter and allows a higher proportion of porous structure to be maintained in a product when the material is formed into a molded product.