A charged particle beam device of the present invention has a signal processing function of acquiring a secondary signal obtained when a charged particle beam is caused to scan at a low speed not subjected to a band limitation of an electrical signal path, and a secondary signal obtained when a charged particle beam is caused to scan at a high speed subjected to the band limitation of the electrical signal path, calculating a degradation function (H−1(s)) between the plurality of secondary signals, and using an inverse function thereof as a correction filter; and a function of updating a parameter of the correction filter to an optimal value as needed or at given timing. Accordingly, the charged particle beam device can perform optimum image restoration even when a detector or an amplifier circuit that constitutes the electrical signal path degrades with time.