An embodiment is to provide a technique that continuously applies a certain amount of an electron beam to a sample by selecting a beam applied to the sample from an electron beam emitted from an electron source in a scanning electron microscope. A charged particle apparatus is configured, including: a mechanism that detects the distribution of electric current strength with respect to the emitting direction of an electron beam emitted from an electron source; a functionality that predicts a fluctuation of an electric current applied to a sample by predicting the distribution of the electric current based on the detected result; a functionality that determines a position at which a beam applied to the sample is acquired based on the predicted result; and a mechanism that controls a position at which a probe beam is acquired based on the determined result.