A processer of an optical module is configured to control a voltage signal having a frequency for causing a movable mirror to resonate, and perform an intensity acquisition process. The intensity acquisition process is a process of acquiring a measurement light intensity of the interference light of the measurement light M times at a first time interval based on the frequency in each of a plurality of cycles among P cycles continuous in the voltage signal, acquiring an addition value of a plurality of the measurement light intensities mutually corresponding for the same number of times, acquiring a laser light intensity of the interference light of the laser light N times at a second time interval based on the frequency in each of the plurality of cycles, and acquiring an addition value of a plurality of the laser light intensities mutually corresponding for the same number of times.