An endoscope adapter for use with an endoscope is provided. The endoscope includes an endoscopic insertion section subject to be inserted into an object subject to inspection and the endoscope adapter so that the endoscopic insertion section has an insertion section electrodes the endoscope adapter comprises a lighting section for emitting light to the object and an adapter electrode section connected to the lighting section. The adapter electrode section comprises: an elongated hollow casing having an opening section at one end in the longitudinal direction of the casing and a columnar electrode terminal configured to be movable in the longitudinal direction in the hollow casing and capable of projecting from the longitudinal direction end of the hollow casing. The inner diameter of the opening section is equalized to the outer diameter of the electrode terminal. It is possible to provide an endoscopic apparatus and an endoscope adapter having an endoscope adapter and an endoscopic insertion section not so significant in sizes being capable of closing an opening section in a state where the endoscope adapter is attached to the endoscopic insertion section and being capable of maintaining the electrode terminal clean for a prolonged period.
