To provide a digital test plug available for both CTT and PTT, and capable of preventing unexpected accidents, such as, electrical shocks and measuring electric power, and so on.

The digital test plug includes: common conductors 24, disposed for each phase so as to allow integrated succession of live-line conductor portions 25 and non-live line conductor portions 26, contacting a power supply-side conductor and a load-side conductor respectively; an insulating support portion 22, projected to support a base end portion so that each common conductor 24, having the housed base end portion can be inserted between the power supply-side conductor and the load-side conductor of a test terminal; current detecting coils 27 for detecting a current running to each common conductor 24; voltage-detecting electrodes 28 for detecting a voltage of each common conductor 24; an A/D converter for converting current signals and voltage signals to be output from the current-detecting coils 27 and the voltage-detecting electrodes 28 into digital information; and a digital tester portion 30 housed in the insulating support portion 22 so that a display portion 32 displaying a measured current and voltage is exposed to the outside.