A processor for an endoscope or the like that assists an endoscopic examination using an appropriate reference image is provided. A processor for an endoscope includes an image acquisition unit that acquires an endoscope image; a region acquisition unit that inputs the endoscope image acquired by the image acquisition unit to a first learning model that outputs a target region corresponding to a predetermined region to be photographed when the endoscope image is input to acquire the target region; and an image output unit that outputs the endoscope image acquired by the image acquisition unit and an index indicating the target region acquired by the region acquisition unit with the endoscope image and the index superimposed.