Control device of exhaust sensor

A control device of an exhaust sensor controlling an exhaust sensor arranged in an exhaust passage in an internal combustion engine and detecting a specific component in exhaust gas, wherein

• the exhaust sensor comprises an element body provided with an electrochemical cell, a protective layer formed on an outer surface of the element body and comprised of a porous ceramic, and a heater supplied with electric power from a battery and heating the element body and the protective layer,
• the control device comprises a battery voltage detection part configured to detect a voltage of the battery, and a heater control part configured to set a target temperature of the electrochemical cell and control the electric power supplied from the battery to the heater so that the temperature of the electrochemical cell becomes the target temperature, and
• the heater control part is configured to set the target temperature to a first temperature after startup of the internal combustion engine until the voltage of the battery detected by the battery voltage detection part recovers to a predetermined voltage, and switch the target temperature from the first temperature to a second temperature when the voltage of the battery detected by the battery voltage detection part recovers to the predetermined voltage, the first temperature being a temperature lower than an operating temperature of the electrochemical cell and at least a lowest temperature at which a Leidenfrost phenomenon occurs at an outer surface of the protective layer, and the second temperature being a temperature of the operating temperature or more.