To provide a crystallizing method by which crystals having the average particle size larger than usual can be manufactured by so-called a vaporizing/crystallizing method.

This crystallizing method comprises a step of precipitating crystals of a compound by vaporizing a solvent from a compound-dissolved solution, a step of dissolving part of the precipitated crystals by adding another solvent capable of dissolving the crystals and a step of vaporizing another solvent from another compound-dissolved solution containing the residual crystals.