A temperature probe for use in a medical thermometer. The temperature probe includes a probe body and a hollow tip member secured to the probe body. The hollow tip member further has an outer wall as a thermal contact surface, an inner wall inside the outer wall, a thermal isolation space formed between the outer wall and the inner wall, and a hollow cavity surrounded by the inner wall. A thermal sensor is disposed within the hollow tip member so as to sense the temperature of the thermal contact surface and produce a temperature signal. A set of transmission wires is connected to the thermal sensor to pass the temperature signal.