An oxygen sensor device consisting a cylindrical tube of a ceramic solid
electrolyte having an oxygen ion conducting property, a reference
electrode formed on an inner surface of the cylindrical tube, and a
measuring electrode formed on an outer surface of the cylindrical tube at
a position at least opposed to the reference electrode, wherein a ceramic
layer is formed on the outer surface of the cylindrical tube, the ceramic
layer having an opening portion for exposing the surface of the measuring
electrode and incorporating a heat-generating member therein, the
heat-generating member being buried surrounding the opening portion. The
oxygen sensor device as a whole has a cylindrical shape relaxing the
concentration of thermal stress and exhibiting excellent thermal shock
resistance. With the heat-generating member being buried near the sensing
portion, the sensing portion is heated up to a predetermined activating
temperature within short periods of time exhibiting an excellent sensor
response.