Endoscope System

An endoscope system comprising:

• an objective optical system that is provided at an insertion portion tip and that acquires a subject image;
• an optical path division means for dividing the subject image into two optical images with different focuses;
• an imaging element that forms the two optical images with different focuses at the same time to acquire two images;
• an image correction means for correcting the two images acquired by the imaging element so that differences other than the focuses become substantially the same;
• and
• an image combination processing unit that selects an image with a relatively high contrast in predetermined corresponding areas between the two images corrected by the image correction means to generate a combined image, wherein
• the optical path division means is a polarization beam splitter, and
• a crystal filter including a crystal shaft forming 45 degrees relative to an incident surface of the polarization beam splitter is arranged on an object surface of the polarization beam splitter.