We have reported that operating a continuously variable transmission (CVT) metal belt over a long time results in formation of austenite (Gamma phase) at the topmost surface of pulleys. In general, martensite arising from heat treatment forms at the surface of pulleys and gears. Therefore, the sliding surface has a body-centered cubic (BCC) metal structure, and transformation to and existence of austenite (Gamma phase) is difficult unless there is a thermal history exceeding the eutectoid point. We have made attempts to accurately measure the sliding surface temperature for verification, but many parts rotate inside an operating CVT and measurement of the pulley surface temperature was difficult. To overcome this issue, we newly developed a non-contact temperature measurement system and reported on measurement near the actual contact portion to predict the temperature of the actual contact portion using the heat equation.