A charged particle beam apparatus that acquires a scanned image by scanning a sample with a charged particle beam and detecting charged particles emitted from the sample, the charged particle beam apparatus comprising: a plurality of detection units that detect charged particles emitted from the sample; and an image processing unit that generates the scanned image based on a plurality of detection signals outputted from the plurality of the detection units, the image processing unit performing: a process of acquiring the plurality of the detection signals at an irradiation position of the charged particle beam; a process of extracting a maximum value and a minimum value from among signal amounts of the plurality of the acquired detection signals, and calculating a difference between the maximum value and the minimum value; a process of calculating a sum total of the signal amounts of the plurality of the detection signals; and a process of determining a pixel value of a pixel of the scanned image corresponding to the irradiation position based on a sum of a first value that is obtained based on the sum total of the signal amounts of the detection signals and a second value that is obtained based on the difference between the maximum value and the minimum value of the signal amounts of the detection signals. a plurality of detection units that detect charged particles emitted from the sample; and an image processing unit that generates the scanned image based on a plurality of detection signals outputted from the plurality of the detection units, the image processing unit performing: a process of acquiring the plurality of the detection signals at an irradiation position of the charged particle beam; a process of extracting a maximum value and a minimum value from among signal amounts of the plurality of the acquired detection signals, and calculating a difference between the maximum value and the minimum value; a process of calculating a sum total of the signal amounts of the plurality of the detection signals; and a process of determining a pixel value of a pixel of the scanned image corresponding to the irradiation position based on a sum of a first value that is obtained based on the sum total of the signal amounts of the detection signals and a second value that is obtained based on the difference between the maximum value and the minimum value of the signal amounts of the detection signals. a process of acquiring the plurality of the detection signals at an irradiation position of the charged particle beam; a process of extracting a maximum value and a minimum value from among signal amounts of the plurality of the acquired detection signals, and calculating a difference between the maximum value and the minimum value; a process of calculating a sum total of the signal amounts of the plurality of the detection signals; and a process of determining a pixel value of a pixel of the scanned image corresponding to the irradiation position based on a sum of a first value that is obtained based on the sum total of the signal amounts of the detection signals and a second value that is obtained based on the difference between the maximum value and the minimum value of the signal amounts of the detection signals.