An endoscope 2 includes: a concave lens 41 a concave lens 42 an image-acquisition element 34 an image-forming optical system 32 that forms an image of a beam passing through the concave lens 41 and an image of a beam passing through the concave lens 42 in a common area on an image-acquisition surface of the image-acquisition element 34 a prism optical system 43 and a light-shielding part 47. The beam passing through the concave lens 41 and the beam passing through the concave lens 42 enter the prism optical system 43, which makes the two beams intersect each other, and the two beams are emitted toward the image-forming optical system 32. The light-shielding part 47 selectively shields one of the two beams exiting the prism optical system 43.
