A data analysis device (1) according to the present disclosure includes a data collector (131) and a data organizer (135). The data collector (131) collects an input signal that is input from an apparatus connected to the data analysis device (1). The data organizer (135) removes, from among waveforms included in the input signal collected by the data collector (131), a waveform that has an appearance frequency lower than a reference frequency. The data organizer (135) generates learning data by collecting, from among the waveforms included in the input signal, waveforms that have an appearance frequency higher than the reference frequency.