To provide an automatic input means for the measurements of a mercury column clinical thermometer and an automatic body temperature measurement process.

This device includes an end detection guide 3, a body temperature memory detection guide 4, and a pointer 5 in order to hold a clinical thermometer 2 in position on the pedestal part 1a of a clinical thermometer storage part 1. The body temperature measured is calculated by predetermining the relationship between the positions of the upper and lower ends of graduations and the body temperature, optically detecting the end position of mercury by means of a light source 7 and a light receiving part 8, and performing a calculation process using a body temperature measurement processing part 9.