The thermal probe method is capable of measuring ion temperature using the heat flow from plasma (Qplasma) versus the bias voltage (Vp) characteristic. Considering the heat transition phenomenon in the probe, we designed the thermal probe in order to obtain the Qplasma-Vp as well as the Ip-Vp characteristics. We performed a preliminary experiment of the thermal probe measurement in the divertor simulator MAP-II, and discuss the results and the assignments of the thermal probe method.