A probe thermometer comprises a main body, a probe, a self-tapping thread, a temperature sensing unit and a display unit. The interior of the main body has a circuit board. The probe includes a measuring end and a coupling end which couples the main body. The self-tapping thread is formed on the measuring end. The temperature sensing unit is disposed within the probe and the temperature sensing unit is electrically connected to the circuit board. The display unit is disposed on the main body. The display unit, the temperature sensing unit and the circuit board are electrically connected. Thereby, the probe thermometer of the instant disclosure is convenient and effectively reduces cost.