Abstract: An endoscope having an insertion portion to be inserted into an object to be observed, includes: a substantially tubular holder member mounted to the insertion portion and having an open front end portion including a shoulder surface surrounded by an axial wall; a lens barrel holding an objective lens system and received in the holder member; and a light-transmissive closure member fitted into a front opening defined by the axial wall, and fixed to the front opening by a bonding agent interposed between an outer circumferential surface of the closure member and an opposing inner circumferential surface of the open front end portion of the holder member, wherein a space axially adjoining the shoulder surface is defined between an outer circumferential surface of a front end portion of the lens barrel and an opposing inner circumferential surface of the holder member.

Abstract: An imaging unit at a tip end portion of an insertion section has a board on which the image pickup device is installed, a cable through which a signal is input to and output from the board, and a ground bar which is provided so as to protrude from the surface of the board and is connected to a ground of the board. In a distal portion of the cable on the imaging unit side, a shield part is connected to the ground of the board through the ground bar and a core line is directly assembled on the board. The ground bar supports the cable on the board such that the height of the cable in the vicinity of a board-mounting portion of the cable becomes greater than or equal to a predetermined value.

Abstract: An endoscope having an insertion portion to be inserted into an object to be observed, includes: a substantially tubular holder member mounted to the insertion portion and having an open front end portion including a shoulder surface surrounded by an axial wall; a lens barrel holding an objective lens system and received in the holder member; and a light-transmissive closure member fitted into a front opening defined by the axial wall, and fixed to the front opening by a bonding agent interposed between an outer circumferential surface of the closure member and an opposing inner circumferential surface of the open front end portion of the holder member, wherein a space axially adjoining the shoulder surface is defined between an outer circumferential surface of a front end portion of the lens barrel and an opposing inner circumferential surface of the holder member.