The invention provides a thermometer. The thermometer is used for monitoring temperature of the armpits, groins, the forehead, the liver portion or the abdomen. The thermometer is provided with a shell body and a probe, wherein the probe and the shell body are integrated or the probe extends out of the shell body, sensors are arranged on the inner surface of the shell body, the outer surface of the shell body and the probe independently extending out of the shell body or inside the shell body, and the sensors are used for detecting whether the thermometer is partially or wholly covered, and/or determining the covering degree.