PROBLEM TO BE SOLVED: To provide a preparation for external use that inhibits biofilm formation of an acne bacterium as a precipitating cause of pimple, effectively prevents or treats pimple, and has high safety and stability.SOLUTION: Culture solution of malassezia genus fungus inhibits the biofilm formation of the acne bacterium. By using the culture solution of malassezia genus fungus together with an antimicrobial agent, the antifungal to the acne bacterium is improved comparing with the case of the antimicrobial agent only. In addition, the preparation for external use containing the culture solution of malassezia genus fungus and the preparation for external use containing the culture solution of malassezia genus fungus and the antimicrobial agent exhibit an excellent pimple prevention and symptom moderating effect, and has high safety and stability. Thus, the acne bacterium biofilm formation inhibitor is effective for pimple prevention and the symptom moderation.
