To provide an OCT (optical coherence tomography) probe confirmable in the measuring position in an endoscope.

A dichroic surface 628a is formed at the end face of a half-ball lens 628A, and a diffusion body 628C is mounted onto the dichroic surface 628a. When multiplexed light of measuring position confirmation light Le being visible light and measuring light L1 being non-visible light, is supplied to the OCT probe, the measuring light L1 is reflected by the dichroic surface 628a and emitted toward a measured object S, while the measuring position confirmation light Le is incident to the diffusion body 628C and diffused to emit light so as to be visible in the endoscope. The light emitting diffusion body 628C is visualized in the endoscope to confirm the measuring position.