Today the vacuum tube is still used for the professional music instrument such as a guitar amplifier, in order to provide specific sound characteristics by the non-linearity of the amplification property. Also, it is well known that the sound is greatly different depending on the tube manufactures. However, the physical reason has not been clarified even though the vacuum tube is tailored based on the original I-V characteristics, which was demonstrated in the 1940s. This paper describes the construction of the measurement system for the vacuum tube with high precision static characteristics.