PURPOSE: To obtain the estimation method of a test equipment which method can define whether disconnection or imperfect wiring exists in a measuring route.

CONSTITUTION: Tips of the whole probes 3 are connected with a conductive region 11 where the whole probes 3 can be shorted on the same surface, and shorted. Thereby a return route of current which returns from a tester 1 to the tester 1 through one probe out of a plurality of the probes 3 is formed. By operating the tester 1, one of the probes 3 is grounded via a wiring 2 connecting the tester 1 with the probe 3, and currents are applied to all of the other probes 3 from a current source in the tester 1. By measuring voltages generated in all current sources in the tester 1 which apply the currents, the route where disconnection or imperfect wiring exists can be defined.