PROBLEM TO BE SOLVED: To provide an optical coherence tomography image generating apparatus, when a nozzle is inserted into an oral cavity of a patient, capable of preventing fogging of a mirror in the nozzle.SOLUTION: An optical coherence tomography image generating apparatus distributes laser beam from a light source 11 into measuring light to be applied to a subject, and reference light to be applied to a reference mirror 21, analyzes interfering light formed by synthesizing scattering light reflected and returned from the subject, and reflected light reflected by the reference mirror 21, and generates an optical coherence tomography image. The optical coherence tomography image generating apparatus includes: a warming device 4 a diagnosis probe unit 30 for collecting the scattering light returned by reflecting the measuring light from the subject a scanning means 33 for changing the irradiation direction of the laser beam introduced into the diagnosis probe unit 30 an opening part 37b for collecting the scattering light formed by applying the measuring light from the scanning means 33 to the subject and a nozzle 37 detachably attached to the diagnosis probe unit 30. The warming device 4 warms a mirror M1 provided on the nozzle 37.
