An endoscope apparatus is an endoscope that is inserted into a sinus cavity of a subject, has a flexible insertion portion, and can irradiate illumination light from the distal end of the insertion portion toward the subject in the sinus cavity. A mirror, and an illumination mechanism that irradiates the subject with illumination light from the endoscope in a manner different from the other directions in a predetermined direction within the illumination light irradiation range.内視鏡装置は、被検体の副鼻腔内に挿入され、可撓性を有する挿入部を有し、挿入部の先端から副鼻腔内となる被検体に向けて照明光を照射可能な内視鏡と、被検体に対して、照明光の照射範囲のうち所定の方向において他の方向とは異なる態様で内視鏡から照明光を照射する照明機構と、を有する。
