Abstract: An electronic clinical thermometer capable of high-precision measurement within a shorter period of time. The electronic clinical thermometer for predicting an equilibrium temperature based on a temporal change in actual measurement value of a measurement target temperature detected by a temperature detection element includes a prediction value derivation unit which derives a plurality of prediction values from actual measurement values in accordance with a plurality of prediction equations, a selection unit which selects one of the plurality of prediction equations based on the selected prediction equation, and a display output which displays a prediction value result based on the selected prediction equation.