To provide a simple arrangement for determining a loading state of a wafer with respect to an adsorption face of an electrostatic chuck.
In a charged particle beam device with function of irradiating a sample with a primary charged particle beam, an electrostatic chuck for adsorbing the sample is provided with a slanted hole or notch. The electrostatic chuck is further provided with: a pair of a floodlight and a light receiver disposed such that a slanted optical axis passes through the slanted hole or notch; and a controller for determining the loading state of the sample with respect to the electrostatic chuck by means of an output signal from the light receiver. The controller determines the loading state of the sample by means of the output signal from the light receiver when the sample is lowered by an elevator to intercept the optical axis.
Yuji Toda
Shigemi Iwasaki