Abstract: A sound source direction detector comprises FFT analysis sections (103(1) to 103(3)) for generating a frequency spectrum in at least one frequency band of acoustic signals for each of the acoustic signals collected by two or more microphones arranged apart from one another, detection sound identifying sections (104(1) to 104(3)) for identifying a time portion of the frequency spectrum of a detection sound which obtains a sound source direction from the frequency spectrum in the frequency band, and a direction detecting section (105) for obtaining the difference between the times at which the detection sound reaches the microphones, obtaining the sound source direction from the time difference, the distance between the microphones, and the sound velocity, and outputting it depending on the degree of coincidence between the microphones of the frequency spectrum in the time portion identified by the detection sound identifying sections (104(1) to 104(3)) in a time interval which is the time unit to detect the so