The purpose of this study was to examine the biofi lm removing and antimicrobial effects of microbubbled tap water and other functional water. The biofi lm removal test showed that the activity of microbubbled tap water against the biofi lm of Candida albicans and Streptococcus mutans was signifi cantly higher than that of ordinary tap water (p<0.01). When the antimicrobial activities of two types of functional water were compared, the activity of electrolyzed hypochlorite water was signifi cantly stronger than that of the ozonated water (p<0.01). The antimicrobial effect of the electrolyzed hypochlorite water was increased in the microbubbled form, and was stronger than microbubbled tap water. The same results were obtained not only for biofi lms, but also for planktonic microbes. Our results demonstrated that the microbubbled water showed strong biofi lm removing effects. Moreover, the application of functional water, such as electrolyzed hypochlorite microbubbled water was effective for both removing and sterilizing biofi lms.