A scanning microscope includes: a charged particle beam source configured to output a charged particle beam to be emitted to a sample; a detector configured to detect charged particles from the sample; and a controller configured to control the charged particle beam source and the detector, wherein the controller changes one or more variable parameters to determine a plurality of different parameter value sets, acquires a measurement result of a temporal change of absorption current in a target sample material under each of the plurality of different parameter value sets, and, based on the measurement results, selects a parameter value set for use in measurement of the target sample from the plurality of different parameter value sets.