An infrared thermometer includes a proximity sensor, an infrared sensor and a micro controller unit. The micro controller unit determines whether or not the infrared thermometer has contact with an object to be measured, using the proximity sensor. The micro controller unit measures the amount of infrared radiation using the infrared sensor at a time when determining that the infrared thermometer has contact with the object to be measured. The micro controller unit calculates a temperature of the object to be measured, based on the amount of infrared radiation.