It is an object to detect a sound wave without changing a direction of an acoustic element even if light is radiated in any direction. This object is achieved by means of a driving device 3 that drives so as to radiate light in a predetermined direction to an advancing direction of the catheter 101 and an acoustic element 1 that receives a sound wave generated by the radiated light, in which the acoustic element 1 is provided in a circumference direction of the catheter 101 and provided in a direction having a predetermined angle to an advancing direction of the light. Furthermore, a plurality of acoustic elements 1 are arranged in an array to form an acoustic element array 10.
