Abstract: A sintered body for a humidity sensor is formed by baking a blend at 1,000.degree. to 1,400.degree. C., the blend comprising ZnO, Cr.sub.2 O.sub.3, V.sub.2 O.sub.5 and M.sub.2 O where M.sub.2 O is at least one metal oxide selected from Li.sub.2 O, Na.sub.2 O and K.sub.2 O. A pair of electrodes are each attached to the corresponding surface of the sintered body to obtain a humidity sensor of metal oxide which is relatively low in its resistive value and stable in its aging characteristic.

Abstract: A method of manufacturing a voltage-nonlinear resistor which has a substantially symmetrical voltage-current characteristic and a large voltage-nonlinearity coefficient and which is thus well resistant to surge voltage. The method comprises: preparing a ZnO-based composition containing metal zinc, at least one metal oxide such as bismuth oxide and at least one spinel type crystalline compound such as spinel type crystalline chromium compound, shaping the ZnO-based composition to form a body, and sintering the body of composition in the air at 1,000.degree. C. or more.