Abstract
Production of the guitar depends on the experience of the skilled guitarmaker. The guitarmaker also evaluates the sound quality of the guitar by the method called as the tapping. The method depends on the experience of the guitarmaker, too. Therefore, it is desired that the technological production method is developed. The paper presents what kinds of information is physically obtained by tapping. The results are as follows. (1) Analysing sharp sound there is a dominant peak at a frequency. (2) There is a correlation between sound quality and vibration characteristics (i.e.) natural mode and frequency are correlated.