An oxygen sensor utilizes a chrome oxide compensating resistor (5) in series with a titania sensing resistor (3). The chrome oxide resistor (5) not only compensates for the effects of temperature on the titania sensing (3) resistor, but since it exhibits (p) type behavior while the titania exhibits (n) type behavior in the presence of gaseous oxygen, the sensitivity of the sensor is increased. The resistors (3, 5) can be applied as a film to a substrate (7) or they can be formed as discrete chips. Substantial quantities of alumina and glass can be added to the chrome oxide without affecting oxygen sensitivity although the electrical resistance rises substantially.