PROBLEM TO BE SOLVED: To provide an endoscope distal end portion which has improved assemblability by securing a sufficient region for applying an adhesive for sealing on an outer peripheral part of an observation window to prevent the occurrence of optical flare and vignetting inside a field of vision.SOLUTION: An endoscope distal end portion 21 includes: an optical system including an observation window 31； an image pick-up device for converting an optical image to a picture signal； a holding frame for holding the optical system； a distal end rigid part where the holding frame is fit； a distal end cover 30 having a hole part where the observation window 31 is exposed for covering the distal end rigid part 21； and a non-transparent adhesive part 36 which seals a gap between the observation window 31 and the distal end cover 30 and has a thin film layer formed in a position corresponding to a counter side direction of a light receiving part of the image pick-up device and a thick film layer which is thicker than the thin film layer and is formed in a position corresponding to a diagonal direction of the light receiving part.SELECTED DRAWING: Figure 2【課題】光学フレア、視野内ケラレなどが発生しないようにするための観察窓の外周部に封止用の接着剤を塗布する十分な領域を確保することで、組立性が向上する内視鏡先端部を提供する。【解決手段】内視鏡先端部２１は、観察窓３１を含む光学系と、光学像を映像信号へ変換する撮像素子と、光学系を保持する保持枠と、保持枠が嵌合される先端硬質部と、観察窓３１が露出する孔部を備え、先端硬質部２１を覆う先端カバー３０と、観察窓３１と先端カバー３０との隙間を封止し、撮像素子の受光部の対辺方向に対応した位置に形成された薄膜層および薄膜層よりも厚く受光部の対角方向に対応した位置に形成された厚膜層を有する非透明な接着部３６と、を具備する。【選択図】図２
