Gas sensor element and gas sensor

A gas sensor element comprising:

• an inner space into which a measurement gas is introduced through a diffusion resistor;
• a first oxygen pump cell including a first solid electrolyte body having oxygen ion conductivity, and first and second electrodes formed on both opposite surfaces of the first solid electrolyte body, the first electrode facing the inner surface so that oxygen can be introduced into or discharged from the inner space to adjust oxygen concentration in the inner space by applying a voltage between the first and second electrodes;
• a second oxygen pump cell including a second solid electrolyte body having oxygen ion conductivity, and third and fourth electrodes formed on both opposite surfaces of the second solid electrolyte body, the third electrode facing the inner surface so that oxygen can be introduced into or discharged from the inner space to adjust the oxygen concentration in the inner space by applying a voltage between the third and fourth electrodes;
• and
• a sensor cell including a third solid electrolyte body having oxygen ion conductivity, and fifth and sixth electrodes formed on both opposite surfaces of the third solid electrolyte body, the fifth electrode facing the inner surface, a current flowing between the fifth and sixth electrode being an output of the gas sensor element indicative of concentration of a specific gas component contained in the measurement gas;
• wherein
• the first electrode and the third electrode are disposed opposite to each other across from the inner space, and
• the second electrode and fourth electrode are exposed to a common reference oxygen concentration gas.