An event detecting apparatus capable of high-precision detection of an event even by use of a narrow-band signal comprises: a plurality of antennas 21 that receive radio waves transmitted from a transmitter, a correlation matrix operation unit 22 that expresses signals received by the plurality of antennas 21 as received vectors, to operate a correlation matrix on the basis of the received vectors, an eigenvector operation unit 23 that performs eigenvalue expansion of the correlation matrix operated by the correlation matrix operation unit 22, to operate eigenvectors covering a signal subspace, and an event detecting unit 24 that detects a temporal change in the eigenvectors operated by the eigenvector operation unit 23, to detect an event.