Direction detection device, phase difference table acquisition method, direction detection method, and direction detection program

This direction detection device for detecting the arrival direction of a received wave comprises: a plurality of antennas that are aligned in at least one-dimensional direction; a phase difference application unit for applying different phase differences according to the received wave arrival direction; a storage unit for storing, for each combination of two antennas, a phase difference table associating phase differences between the two antennas and received wave arrival directions; a detector for detecting the phase difference between two antennas on the basis of the received wave; an extractor for extracting a plurality of received wave arrival directions corresponding to the phase difference detected by the detector from a phase difference table in accordance with a combination of two antennas; and a comparator for comparing received wave arrival directions corresponding to a plurality of phase differences and acquiring a matching received wave arrival direction as a detection result.