PURPOSE: To reduce the resistance value deviation of a nonlinear resistor by making the carbon concentration of a sintered body provided with high- resistance layers and electrodes lower than a specific wt.%.

CONSTITUTION: High-resistance layers 2 are formed by applying an insulator to the side faces of a sintered body 1 and baking the insulator at a prescribed temperature in the air. Then, after polishing both end faces of the sintered body 1 to a prescribed thickness with a grindstone and sufficiently cleaning both polished ends by means of a cleaning machine, electrodes 3 are formed on both end faces. The carbon concentration of the sintered body 1 prepared in such a way is suppressed to ≤0.05%. Therefore, the resistance distribution in this nonlinear resistor can be made uniform by reducing the deviation of the resistance value of the resistor.