PROBLEM TO BE SOLVED: To prevent generation of luliconazole an isomer due to influences of moisture, light, and the like, and to provide means to improve stability thereof.SOLUTION: Provided is a luliconazole crystal obtained by recrystallization using a solvent selected from a mixed solvent of ethyl acetate-n-hexane or a mixed solvent of ethanol-water. The crystal of luliconazole is produced by a production method comprising steps of: evaluating the crystal as a crystal having a low proportion of Z isomer and being suitable for a pharmaceutical formulation using as an index that a surface free energy of a luliconazole crystal is 28 mJ/mor less and a proportion of a polar component in the surface free energy is 35% or less; and selecting the crystal evaluated in the above step as a crystal having a low proportion of Z isomer and being suitable for a pharmaceutical formulation.
