There is provided an invention to implement a multichannel analyzer capable of executing high-precision measurement in short measurement time. The invention is an improvement of a multichannel analyzer for receiving pulse signals having respective peak values corresponding to radiation energy, and generating a histogram by selecting the respective peak values of the pulse signals on the basis of a lower limit value, and an upper limit value. The multichannel analyzer is characterized in comprising a conversion means for converting a voltage level of the pulse signal into a digital data block expressed in the same unit as that for the peak value at a predetermined sampling rate, a peak detector for detecting the peak value out of the digital data blocks of the conversion means, and a histogram analyzer for finding the number of occurrence times for each of the peak values, as selected after detection by the peak detector.