To prevent the occurrence of deposit on the cover of an intake O2 sensor arranged in the intake passage of an internal combustion engine during the intermittent stop of the engine in a control device for controlling the heater of the sensor.

This control device is provided with the intake O2 sensor with a heater arranged in the intake passage of internal combustion engine. When it is discriminated that the engine is on operation (steps 100 and 102), a heater control is carried out in such a way that the sensor element of the intake O2 sensor has a target temperature (step 106). When it is judged that the engine is intermittently stopped (steps 100 and 102), the heater control targeting the sensor is stopped (step 104).