Shamisen is musical instrument that is difficult in tuning because of a lot of tuning patterns and noisy sounds. In this study, the tuning of shamisen has been investigated and an assist device for exclusive use of the tuning been designed. As a result of this study, a trial product of the egg type device referring to the tuning instrument, choshibue, used to tune the shamisen has been developed and the usability to the shamisen players been tested. The device has high evaluation and its products will be commercial available next year.