An endoscope system (1) includes an insertion portion (4) to be inserted into a subject, an insertion portionIs provided in the entrance (4), and acquires a first object image from the first region of the subjectA direct viewing observation window (11a) provided in the insertion portion (4) and different from the first regionA side view observation window (11 b) for acquiring a second object image from the second region of the subject,Detects rotation around the axis with the longitudinal direction of the insertion part (4) as the axis, generates inclination informationA tilt angle detection unit (17) for forming a first object image and a second object on the display screenAnd a subject image are arranged side by side, and based on the inclination information, a first objectAn image signal representing a state in which the relative position of the second object image with respect to the image is rotated is generatedAnd a video processor (32) for performing a video processing.内視鏡システム（１）は、被写体の内部に挿入される挿入部（４）と、挿入部（４）に設けられ、被写体の第１の領域から第１の被写体像を取得する直視観察窓（１１ａ）と、挿入部（４）に設けられ、第１の領域とは異なる被写体の第２の領域から第２の被写体像を取得する側視観察窓（１１ｂ）と、挿入部（４）の長手方向を軸とした、軸周りの回転を検出し、傾き情報を生成する傾き角度検出部（１７）と、表示画面上で第１の被写体像と第２の被写体像とを隣り合わせて配置するとともに、傾き情報に基づき第１の被写体像に対する第２の被写体像の相対位置が回転した状態を表す画像信号を生成するビデオプロセッサ（３２）と、を備える。
