This demonstaration shows the semiconducting behaviour of a thermistor. A thermistor is a temperature-sensing element composed of semiconductor material which exhibits a large change in resistance proportional to a small change in temperature. Thermistors usually have negative temperature coefficients (NTC) and their resistance decreases as the temperature increases. The experimental setup consists of a thermistor being immersed in the water and a thermocouple is used to monitor the temperature of the water. The resistance change is observed through a digital multimeter which is connected to the thermistor and a hot plate is used to heat up water.