An electronic thermometer of the present invention includes: a temperature sensor for sensing temperature and outputting a digital signal value representative thereof; a temperature conversion data storage unit having at least a first data storage area for storing temperature conversion data of relatively high resolution and a second data storage area for storing temperature conversion data of relatively low resolution; a read-out element for, when the digital signal produced by the temperature sensor is within a first range, reading-out corresponding temperature conversion data from the first data storage area according to the value of the digital signal, and, when the digital signal, produced by the temperature sensor is within second range, reading out corresponding temperature conversion data from the second data storage area according to a selected value of the digital signal, and a display for displaying a temperature corresponding to the temperature conversion data. Whereby, when the temperature is in the first range, high resolutions and high accuracy of indication can be obtained while when the temperature is in the second range, low resolution which may be quite acceptable may be attained. Thereby, the capacity of the temperature conversion data storage unit may be more economically effectively utilized.