The vertical and horizontal directions of an endoscopic image are matched with the vertical and horizontal directions of a monitor screen without impairing the effective area of the endoscopic image. A control device for an endoscope system according to the present disclosure includes a scope rotation angle acquisition unit that acquires a scope rotation angle around an axis in an insertion direction of a scope including an objective lens that is inserted into a body, and the scope rotation. A rotation angle control unit that controls the rotation angle of the optical axis center of the image sensor that captures an image by the scope based on the angle. [Selection] Figure 1【課題】内視鏡画像の有効領域を損なうことなく、内視鏡画像の上下左右方向とモニタ画面の上下左右方向を一致させる。【解決手段】本開示に係る内視鏡システムの制御装置は、体内に挿入される対物レンズを備えるスコープの挿入方向の軸周りのスコープ回転角を取得するスコープ回転角取得部と、前記スコープ回転角に基づいて、前記スコープによる画像を撮像する撮像素子の光軸中心の回転角を制御する回転角制御部と、を備える。【選択図】図１
