PURPOSE: To eliminate an error of measuring temperature due to power supply voltage variations by a temperature measuring unit of an electronic watch and enhance the accuracy of the watch by desplacing time of applying heavy load for driving a step motor or the like and timing of measuring the temperature.

CONSTITUTION: A signal F divided in frequency by a frequency divider 3 operates a step motor M, inverted by a timing generator 11, and conducts a transistor 13 to thereby flow a current through a temperature sensing element 5. Simultaneously, the signal starts operating of a DA converter 10 and applies a stepwise signal C to an inverter 9 together with the output of the element 5. When the inverter 9 reaches a threshold voltage, it stops the converter 10 to thus measure the temperature by the operating time of the converter 10. The output signals 10BW10E of the converter 10 switch the capacitors CAWCD to regulate the oscillating frequency.