The thermistor portion of a thermistor device consists of a mixed sintered body of aY(Cr.sub.0.5Mn.sub.0.5)O.sub.3.bAl.sub.2O.sub.3 made of the perovskite-type compound Y(Cr.sub.0.5Mn.sub.0.5)O.sub.3 and Al.sub.2O.sub.3, or a mixed sintered body of aY(Cr.sub.0.5Mn.sub.0.5)O.sub.3.b(Al.sub.2O.sub.3+Y.sub.2O.sub.3) made of Y(Cr.sub.0.5Mn.sub.0.5)O.sub.3, Al.sub.2O.sub.3 and Y.sub.2O.sub.3. The mole fractions a and b have the relationships 0.05.ltoreq.a<1.0, 0