To provide a resistor built in an electron tube of high reliability to prevent a fatal trouble of voltage dividing impossibility because of breakage of a resistor layer generated in a breakdown voltage treatment process or during actuation in an electron tube, and restrict change of resistance or a partition ratio by the damage to the minimum.

In a resistor provided in an envelope in an electron tube, an insulting substrate 31, a resistor layer 34 having a specified resistance formed on the insulating substrate 31, an electrode layer 33 formed on the insulating substrate 31 and connected to the resistor layer 34, and an insulation coating layer 37 to coat the resistor layer 34 are provided. In part of the resistor layer 34, a parallel resistor 35 comprising plural resistor layer parts 35a disposed in parallel is formed.