An electronic thermometer includes a temperature sensing means for sensing a temperature of a part to be measured, a prediction means fro predicting an equilibrium temperature by using the temperature being sensed, and a temperature display means having a temperature display unit. The temperature display means switches the display of the temperature display unit from the predicted temperature predicted by the prediction means to the actual measured temperature sensed by the temperature sensing means, based on a variation state of a peak of the temperature sensed by the temperature sensing means. Accordingly, a variation in displayed temperature is reduced, when the display switching is performed from the predicted temperature to the actual measured temperature, and a determination of the display switching from the predicted temperature to the actual measured temperature can be achieved by a simple circuit.