An imaging apparatus for diagnosis is connected with a probe including a transmitting and receiving unit transmitting a light transmitted from a light source continuously to the inside of a body cavity and concurrently, receiving a reflected light continuously from the inside of the body cavity, and generates a tomographic image inside the body cavity based on the obtained reflected light by obtaining the reflected light from the transmitting and receiving unit while rotating the transmitting and receiving unit. The apparatus comprises: a mechanism for extracting intensity of the reflected light obtained by a phenomenon that the light transmitted to the transmitting and receiving unit is reflected at the transmitting and receiving unit and a mechanism for judging whether or not the extracted intensity of each reflected light at each rotary angle of the transmitting and receiving unit lies in a range of a predetermined variation width.
