An endoscope system is provided with an insertion portion, a direct-view observation window, a side-view observation window, a video processor, an image processing section configured to remove, overlapping regions between the first image and the plurality of second images and match lengths of sides of the plurality of second images to a length of a side of the first image, and a region of interest detection section configured to detect a region of interest from the plurality of second images. The image processing section performs image processing of canceling the processing of increasing the width of the image region as the distance from the region adjacent to the first image increases for only the second image from which the region of interest is detected among the plurality of second images according to a result of the detection conducted by the region of interest detection section.