A signal processing unit (21) of a charged particle microscope calculates a degradation function (H (s)) of an image, on the basis of detection signals (11) obtained by scanning a charged particle beam (2) at two types of scanning speeds, a scanning speed within the bandwidths of a detector (12) and an amplifying circuit at a subsequent stage of the detector, and another scanning speed exceeding the upper limit of the bandwidths. Then, the signal processing unit creates a one-dimensional correction filter for recovering image quality, from an inverse function (H−1 (s)) of the degradation function, and applies the one-dimensional correction filter to the detection signal recorded at the scanning speed exceeding the upper limit of the bandwidths of the detector and the amplifying circuit at a subsequent stage of the detector, or to a two-dimensional image based on the detection signal.