Nowadays mobile devices maintain a lot of private information such as payment information, personal photographs and so on. In Japan, people are starting to use cellular phones as means of payment like pre-paid cards. If owners lost these devices and someone else picked it up, what would happen? To solve this problem, password is now widely used. In the case of password, it has to be complicated and long enough from the viewpoint of security, however it is troublesome for users to type such a long password. If someone set very easy password to avoid the troublesome process, it would be of no use. To solve both security and usability problem simultaneously, various types of biometrics have been proposed. Among many biometric solutions, since nowadays almost all of cellular phones have cameras, we propose face recognition that utilize these cameras. Through the verification process, users have only to take their facial photo using a camera equipped on mobile devices and wait for about one second. The system is effective enough to be used in the mobile devices in terms of performance, usability and hardware requirement.