LOW TEMPERATURE PROBER

PURPOSE:To speedily and accurately measure the characteristics of a wafer type infrared-ray detecting element by fitting a holding jig to a probe and holding an aperture, and cooling the aperture with liquid nitrogen through the holding jig. CONSTITUTION:The wafer type infrared-ray detecting element 3 is sucked to a liquid nitrogen reservoir 8 filled with the liquid nitrogen 9 through a vacuum suction hole 11. The probe 6 which measures the characteristics of the detecting element 3 is mounted on a probe card 7, the holding jig 5 is fixed to the probe 6, and the aperture 4 which has an opening stopping down the visual field of infrared rays is fitted. In such constitution, the aperture 4 is cooled by heat conduction from the liquid nitrogen reservoir 8 and the visual field of the infrared rays is stopped down and used, so a background radiation quantity becomes small and the characteristics of the infrared detecting element such as sensitivity and a signal-to-noise ratio can speedily and accurately be measured in the wafer state.