Provided is an endoscope system capable of obtaining good image quality from the center area of the screen to the peripheral area. An objective optical system OBL, an optical path splitting section 20 for splitting the subject image obtained by the objective optical system OBL into two optical images of different focuses by using two prisms, and one image pickup element And an image synthesis processing section 23 for selecting an image having a relatively high contrast between the obtained two optical images in a predetermined region and generating a composite image, the two prisms , The bonding surfaces are bonded so as to be substantially parallel to each other with the bonding agent interposed therebetween and the bonding surface and the optical axis of the objective optical system OBL form an angle of 45 degrees and the following conditional expression (1) is satisfied As shown in FIG. -10
