An apparatus for observing and photographing a corneal endothelium includes an illumination optical system 28 for projecting each illumination light emitted by a light source 30 for observation and a light source 32 for photography onto a cornea C of a subject's eye E at an angle, an observing and photographing optical system 29 for receiving scattered light reflected by the cornea C with the endothelial layer and observing and photographing it, and an optical system 1 for observing the anterior segment of the eye E. The observing and photographing optical system 29 is provided with a sensor 47 for detecting an image of the endothelium in focus.