To provide the distal end part of an electron endoscope capable of easily detaching an object imaging element unit when disassembling for repair of a distal end part main body to recover it and easily performing the assembling work of the distal end part by exerting no adverse effect on another part even if air bubbles are mixed with the adhesive used for fixing the object-imaging element unit to the unit holding hole of the distal end part in assembly work.

The vicinity 11a of the leading end part of the unit holding hole 11 is formed into a circular cross-sectional shape and an auxiliary cylinder 20 is provided to the leading end part of the unit holding hole 11 so that the outer periphery thereof is fitted and inserted in the unit holding hole 11 and the leading end part of the object-imaging element unit 8 is fitted and inserted in the inner periphery therein. The outer peripheral part of the auxiliary cylinder 20 is sealed by a first elastic adhesive 21, the unit holding hole 11 behind the auxiliary cylinder 20 is filled with a second elastic adhesive 12 while the peripheral space of the object-imaging element unit 8 is filled with a hard adhesive 13 changed to a hard state from a flowable state by heating in the auxiliary cylinder 20 to be sealed.