A contact detecting apparatus is a contact detecting apparatus for emitting illumination light onto a body tissue which is in contact with a distal end and detecting contact between the body tissue and a measurement probe 3 which receives return light of the illumination light scattered from the body tissue, wherein the contact detecting apparatus includes a laser light source configured to emit laser light having a wavelength shorter than a wavelength of the illumination light and emitted onto a specified region of the body tissue via the measurement probe, a photoelectric conversion unit configured to convert the light received via the measurement probe into an electric signal, and a signal processing unit configured to determine presence or absence of contact between the distal end of the measurement probe and the body tissue based on whether the electric signal converted by the photoelectric conversion unit includes a component of a beat signal caused by interference of the return light of the laser light scattered from each of the surface of the body tissue and the distal end surface of the measurement probe.
