1. A semiconductor device test system for specifying a portion of a semiconductor device in which leak current occurs, comprising: a magnetic field generator for applying magnetic field to said semiconductor device; a power supply for allowing current to flow through a wiring of said semiconductor device in said magnetic field; a stress detector for detecting a stress occurring to said wiring by allowing current to flow in said magnetic field and outputting stress image data; an observation unit for observing a wiring pattern of said semiconductor device and outputting wiring pattern image data; and an image display unit for displaying stress images and wiring pattern images based on said stress image data and said wiring pattern image data, respectively.