PURPOSE: To enable the position of a sound source to be accurately detected by providing a mimic sound source with the same angular velocity as that of a sound to be detected in the neighborhood of an object to be detected and obtaining a position wherein the directions of the mimic sound source and the sound to be detected agree with each other.

CONSTITUTION: Acoustic intensity microphones 2a and 2b are provided at two suitable points opposing to an object 1 to be detected and the directions α1 and α2 with maximum acoustic intensity with regard to a sound to be detected. Then, a mimic sound source 4 with the same angular velocity as that of the sound to be detected is provided in the neighborhood of the object 1 and similarly sound source directions θ1 and θ2 and a sound source position lx are obtained. The position lx of the mimic sound source 4 wherein the directions α1 and α2 and those θ1 and θ2 agree with each other at the same time, respectively, is the position (l) of a sound source 3 to be detected. Accordingly, the sound source can be accurately detected regardless of nonaxisymmetry in the directional characteristics of the microphones.