Patent ID: 8525537

Claim:
A contact detecting device, comprising a mechanical probe movable for being in contact with an object to be contacted, a charged particle beam source which generates a charged particle beam to be applied to the object to be contacted, a detector for detecting secondary particles or backscattered particles from the object to be contacted, a calculating device which calculates, from a detection signal from the detector, a feature quantity of a shadow of the mechanical probe projected on the object to be contacted, and a control device which controls the operation of the mechanical probe, wherein: the calculating device calculates a shadow density S(x, y) as the feature quantity of the shadow of the mechanical probe, the shadow density S(x, y) representing a deviation of brightness I z (x, y) at a pixel position (x, y) of an observed image when the mechanical probe is provided with respect to brightness I 0 (x, y) at the pixel position (x, y) of the observed image when the mechanical probe is not provided, and obtains an evaluation value J(z) based on the shadow density S(x, y), the evaluation value J(z) representing a distance between the object to be contacted and the mechanical probe.