CHARGED PARTICLE BEAM DEVICE

PURPOSE:To provide a charged particle beam device which can observe and analyze a specimen of insulated substance in good performance. CONSTITUTION:The current I1 of a primary electron beam emitted by an electron gun 1 is sensed by a Faraday cup 5, and a signal I1 representing the primary electron beam current I1 is stored in a primary electron beam current holding part 6. The secondary electrons and/or reflection electrons from a specimen are sensed by sensors 7, 8. The signals generated by the sensors are fed to a secondary bean current calculator 8, which determines the secondary beam current I2, and a signal I2 representing it is sent to a comparator 10, which conducts a processing of subtracting signal I2 from I1. The output signal therefrom (I2-I2) is sent to another comparator 11. A specimen current sensor 12 measures the specimen current Ia and feeds a signal Ia representing it, Ia, to the latter named comparator 11, which conducts a processing of subtracting Ia from the signal (I1-I2) to generate ((I1-I2)-Ia). A power supply for heating 13 controls a heater 14 so that the output of the comparator 11 nullifies.