PURPOSE: To reduce remarkably the test time and to complete the adjustment in a short time with a very simply way by using plural current output type digital-analog converters connected to a resistance circuit network so as to attain high resolution.

CONSTITUTION: A D/A DAC1 corresponding to a high-order digital input bit and a D/A DAC2 corresponding to a low-order digital input bit are connected to the resistance network and an analog output is obtained at resistance networks R1, R2. In taking a D/A full scale current as 2mA and 0.25mA respectively, the D/A converter having 16-bit resoltion is constituted by taking the ratio of R1 to R2 as 31:1. The high resolution D/A converter possible for massproduction is obtained by the simple constitution. In adopting a test terminal, the test time is reduced remarkably. In using a variable resistor for the resistor R2, the adjustment is simplified and the resolution is improved.