<p>An ear thermometer comprises a cylindrical probe and an accommodating body that accommodates an infrared detection element. The ear thermometer measures the body temperature of a subject from a signal obtained by using the infrared detection element to detect infrared rays that are emitted from a measurement site within the external auditory canal of the subject and are picked up from the tip end of the probe. A plurality of contact sensors capable of detecting whether or not contact is made with an external body are independently provided on the end face of the tip end of the probe or on a side face of the tip end. A projection/detection optical sensor comprising an optical projector that generates light and an optical detector that detects reflected light from the light generated by the optical projector is disposed within the probe. A control section of the ear thermometer is capable of commencing body temperature measurement performed by the infrared detection element if signals that are received from the plurality of contact sensors and indicate whether or not contact has been made and the intensity of the light received by the optical detector satisfy prescribed conditions.</p>
