A data collection device includes a reference signal reception unit that receives a reference signal indicating a first time that is a time measured by an external device, the reference signal being transmitted at first time intervals from the external device, a time signal generation unit that measures a time at second time intervals and generates a time signal indicating a second time that is the measured time, a parameter generation unit that generates a parameter value on the basis of the first time indicated by the reference signal and the second time based on the time signal generated at a point in time when the reference signal is received, a signal reception unit that receives an analog signal indicating a signal waveform of an observed signal, a sampling unit that samples the received analog signal at the second time intervals to generate sampling data, and a data processing unit that performs interpolation processing on the sampling data on the basis of the parameter value.