An oxygen concentration detecting element including a base member made of an electrically insulating material, a heater disposed on an outer surface of the base member, the heater being adapted to generate heat upon being energized, and an oxygen detecting unit disposed in an offset position on the outer surface of the base member in which the oxygen detecting unit is prevented from overlapping with the heater, the oxygen detecting unit including a solid electrolyte layer and a pair of electrodes between which the solid electrolyte layer is disposed.