An endoscope apparatus includes: an endoscope having an insertion section; and a sheath attached thereto so as to cover at least the insertion section of the endoscope, wherein the endoscope apparatus is equipped with: a forward end gap portion formed between the inner surface of an edge portion formed in the forward end portion of the sheath and the outer surface of the forward end portion of the insertion section of the endoscope; and a fluid passage which communicates with the forward end gap portion and which is formed between the inner surface of the sheath and the outer surface of the insertion section of the endoscope, and wherein a liquid feeding passage or a suction passage for passing a cleaning fluid or a sucked object is provided in the fluid passage, and a nozzle section for spraying the cleaning fluid onto an observation window portion in the forward end portion of the insertion section of the endoscope is provided in the forward end gap portion.