To provide an acoustic vibration detector capable of detecting acoustic vibration using an optical microphone and detecting acoustic vibration by rotating the detection direction of sound limitlessly.

The acoustic vibration detector comprises: a rotating mechanism capable of rotating the arrangement state of an acoustic vibration detection module; an optical cable at an incidence side for leading light received by an acoustic vibration detection module to a remote location; and a relay section 22 for relaying the edge of the optical cable to that of another optical cable. Then, the relay section 22 has a first cable set k1, where the edge of a branch cable is arranged on a plurality of circumferences, and a second cable set k2, where the plurality of edges of another optical cable are arranged on a plurality of circumferences while their numbers are different. The cable end of the first cable set k1 and that of the second cable set k2 are arranged opposingly so that they can be rotated with a rotary axis as a center.