Patent ID: 8092375

Claim:
An endoscope insertion portion comprising: an insertion portion body having a distal end and a proximal end, the insertion portion body being configured to be inserted from the distal end into a body cavity; a distal end portion provided at the distal end of the insertion portion body, the distal end portion having a distal end surface; a plurality of image pickup portions, each of the plurality of image pickup portions being configured to observe light; a plurality of observation windows, each of the plurality of observation windows having different outer diameters and being configured to lead incident light to a corresponding one of the plurality of image pickup portions, the plurality of observation windows being disposed on the distal end surface of the distal end portion; an air/water feeding portion configured to spout out a gas or liquid toward the plurality of observation windows, the air/water feeding portion being disposed on the distal end portion; a first aperture portion of a first duct into which a treatment instrument is insertable, the first aperture portion being disposed on the distal end surface of the distal end portion; and a second aperture portion of a second duct for feeding a liquid to a region to be inspected, the second aperture portion being disposed on the distal end surface of the distal end portion; wherein the plurality of observation windows are located to line up on a generally straight line in a spouting direction of the gas or liquid from the air/water feeding portion and one of the plurality of observation windows having the largest outer diameter is disposed on the distal end surface at a position closest to the air/water feeding portion than the other of the plurality of observation windows, and the first aperture portion and the second aperture portion are disposed on the distal end surface outside a spouting area of the gas or liquid spouted out from the air/water feeding portion.