An optical coherent cross-sectional image forming apparatus (100) in which light outputted from a light source (209) is divided (208) into a measurement light and a reference light inside the apparatus (100) and in which a cross-sectional image is formed based on a coherent light, which is obtained from a reflected light obtained by emitting the measurement light to a biological tissue through a probe (101) inserted into a body lumen, and the reference light, wherein there are included a detector (905) for detecting a fact that a transmitting and receiving unit (401) entered inside a guiding catheter (620) for guiding the probe (101) by using data during the axial-direction movement (803) and a controller (907) for stopping (S108,S109) at least a portion of a process associated with from generation to holding of the cross-sectional image based on the optical coherence in a case in which it is detected (S107) by the detector (905) that the transmitting and receiving unit (401) entered inside the guiding catheter (620).
