Gas sensor

Abstract

A gas sensor 100 comprise a sensor element 101 and a control device 95. When a prescribed condition is satisfied, the control device 95 executes, as refresh processing, at least one of: first refresh processing for controlling a main pump cell 21 to pump oxygen from around an outside pump electrode 23 to around an inside pump electrode 22; second refresh processing for controlling a first measurement pump cell 50 to pump more oxygen than in first measurement pump control processing from around the outside pump electrode 23 to around a first measuring electrode 51; and third refresh processing for controlling a second measurement pump cell 41 to pump more oxygen than in second measurement pump control processing from around the outside pump electrode 23 to around a second measuring electrode 44.