Disclosed is a method of evaluating stability of a pharmaceutical preparation containing luliconazole. The method includes measuring an amount of production of an SE form of luliconazole represented by following formula (2), an amount of production of a Z form of luliconazole represented by following formula (3) and an amount of production of an amide form of luliconazole represented by following formula (1) after storage under a severe condition or an accelerated condition, and judging that the stability of the pharmaceutical preparation is high if each of the amount of production of the SE form, the amount of production of the Z form and the amount of production of the amide form is not more than 5% by weight with respect to a compounded amount of luliconazole.