PURPOSE: To make a thermometry time constant by providing a heating part such as a heater to the detection part of the electronic clinical thermometer which samples and processes detection information of a detecting element provided to the detection part and displays temperature on a display part.

CONSTITUTION: The electronic clinical thermometer samples and processes information detected by the detecting element 4 provided to the detection part 2 and displays the temperature on the display part 3. Then, the heater 10 is arranged at the periphery of the detecting element 4 arranged at the detection part 2 to provide the heat part. When a push button 1 is pressed, an electric power source part 8 puts the heater 10, thermometric element 4, etc., all in operation. Namely, when the push button 1 is pressed, electric current flows to respective parts and the heater 10, which heats the detecting element 4 and detection part 2; when the temperature of the detecting element 4 attains to a set temperature, e.g. 35°C, a gate is used to put a display part 7 in operation. Therefore, thermometry is attained within the constant necessary time without any influence of the ambient temperature before the start.