A gas sensor element in which oxidation of electrodes and a heater occurring with continued use is suppressed is provided. The gas sensor element includes a plurality of solid electrolyte layers stacked one over another, and includes an electrochemical cell including a pair of electrodes and a portion of the plurality of solid electrolyte layers existing between the pair of electrodes; a heater part capable of heating the gas sensor element; and a gettering layer located between the plurality of solid electrolyte layers and between the plurality of solid electrolyte layers and each of the pair of electrodes, and gettering impurities in a metal component of the electrodes and the heater part during driving of the gas sensor element.