An instrument measuring the temperature dependence of minority‐carrier lifetimes without contacts is described. The temperature range is 100 to 420 K, and the shortest decay time observed is about 2 &mgr;s. The instrument utilizes the photo decay of microwave power reflected from the sample, therefore, it is a contactless method. As an example, the instrument was applied to high‐quality silicon crystals used in very large scale integrated circuit fabrication. The measured temperature dependence could be explained by the Shockley–Read–Hall theory by assuming a level for the recombination centers at 0.18 eV from the valence band.