A process of controlling an operation of an electric kettle includes the steps of initializing a microprocessor to detect a water temperature via a temperature sensor to set a system parameter; checking a status of a control circuit; determining a preserve temperature of the water; verifying the temperature sensor to protect the temperature sensor from being burnt; determining a condition of the water whether the water is needed to be heated up or preserved; and sending out a control signal to the control circuit in responsive to the condition of the water to heat up the water or maintain the water at the preserve temperature. Therefore, the present invention is adapted to accurately control the whole process of the electric kettle.