Abstract: The invention provides a dual-use infrared thermometer, including a main body and a probe, wherein the probe is formed at the top end of the main body; a hollow sleeve, whose shape is corresponding to the probe to be sleeved onto the probe for forming a forehead-type probe; and a temperature detection device, provided inside the main body to sense the infrared emissions and then convert the emissions into electronic signal, while a build-in temperature calibration procedure is employed to calculate the measured temperature. Alternatively,an interface switch device is provided on the surface of the probe, extending to the internal of the main body to be electrically connected to the temperature detection device. Thus, by detecting whether the hollow sleeve has been sleeved on the probe, the temperature detection device will be activated to switch to either the ear temperature calibration procedure or the forehead temperature calibration procedure.