positive temperature coefficient thermistor is prepared from a sintered body of a ceramic material composition which has as a substrate batio 3 with metallic oxide . there is almost no difference of exothermic temperature even if different voltage is applied to the positive temperature coefficient thermistors . thus , when the present invention is used in countries or areas in which both 110 v and 220 v of commercial voltages are used , almost certain temperature can be obtained without changing voltage by a transformer .