Abstract: A metal oxide resistor for suppressing variations in resistivity in use in an atmosphere at a high temperature or humidity. Such a metal oxide resistor includes a sintered body in which carbon particles having an average grain size of 1 .mu.m or less exist in the grain boundaries of metal oxide particles in an amount of 0.05 to 3 wt %, and electrodes formed on at least two opposing surfaces of the sintered body.

Abstract: There are disclosed a plastic processing method of the pressure of pressureless sintered ceramic body composed of at least one aluminum-containing compound selected from the group consisting of aluminum oxide, aluminum nitride and aluminum oxynitride and at least one hard compound selected from the group consisting of carbides, nitrides and oxides of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten and silicon and mutual solid solutions thereof, the content of said at least one aluminum-containing compound is 5 to 95% by volume, comprising subjecting the ceramic body to plastic deformation at a temperature of 1300.degree. C. or higher, under a stress of 15 kg/mm.sup.2 or smaller and at a strain rate of 10.sup.-3 /sec or less in a reducing atmosphere or in vacuum, and a ceramics-made molded material comprising a composite ceramic body composed of the same as mentioned above.