In an embodiment of the present invention, an OCT probe is configured by including: a thin and long substantially cylindrical sheath whose distal end is closed; an n-reflecting surface body, as an irradiating device, which has n reflecting surfaces (with n being an integer of three or more) and which is provided in a distal end portion of the sheath; a torque transmitting coil, as a rotating device, which is provided along the longitudinal axis of the sheath and which transmits rotational torque for rotating each of the reflection surfaces of the n-reflecting surface body about the longitudinal axis of the sheath; and n fibers (1) to (n), as an n-channel waveguide device, which are provided and fixed in the sheath in a side by side relationship with the torque transmitting coil.