The present invention provides a producing method of powder particles having an average particle diameter on the order of submicrons. Specifically, the producing method is a producing method of powder particles obtained by grinding a product to be ground by using plural grinding media, wherein the grinding media including at least one kind (grinding medium A) having an average particle diameter of 0.01 to 5 times and at least one kind (grinding medium B) having an average particle diameter of 10 to 450 times, with respect to the average particle diameter of the product to be ground before being ground, are used.