To provide a substance separating/recovery method using a superconductive magnetic field that separate and recover substances efficiently, to make the ashes harmless, and to generate zeolite. The method of the present invention includes: (1) a step, wherein the ashes resulting from the incineration of combustible waste are (a) introduced into a first tank 2 to form a liquid that contains, as a solvent, an alkaline aqueous solution or water, air, and electrolytic water, and (b) continuously reinjected into a first substance-separating/recovering device 1A to make the ashes harmless, and (2) a step, wherein clear water, which recovered in the first substance-separating/recovering device 1A and then returned to the first tank 2, is (c) introduced into a second tank 3 to form a heat-treated liquid that contains, an alkaline aqueous solution, and (d) continuously reintroduced into a second substance-separating/recovering device 1B to crystallize that heat-treated liquid into zeolite.