PROBLEM TO BE SOLVED: To provide an endoscopic device having a guide tube member, which is guided so that the inside of an inspection object can be smoothly inspected with a simple structure even when liquid such as water exists.SOLUTION: At the tip end of a guide tube member 22 into which an insertion part 2 is inserted, a capsule-shaped center ring 23 with a front cup 26a and a rear cup 26b is provided which has a space 28 generating buoyance. The buoyancy generated in the space 28 is adjustable by supplying and exhausting compressed air to and from the user side. A tip part 7 can be set in the vicinity of the center location of a piping 51 so that the whole periphery of an internal wall of the piping 51 can be observed as an image obtained by an imaging element of the tip part 7 of the insertion part 2 in a state of being inserted into the piping 51 having water 52 therein.
