Abstract: It is an object of the present invention to enable quick, easy, and inexpensive connections even in a narrow area using an inexpensive device and an inexpensive optical fiber connecting element, thereby achieving high operability and high durability reliability. An optical fiber connecting element includes an optical alignment sleeve having tapered insertion ports formed at opposite ends thereof and having an ejection port opened in an area in which the two optical fibers inserted through the insertion ports are butted against each other, a cyanoacrylate-type glue injected into the insertion ports and the injection port to fix the two optical fibers, and a heat-shrinkable tube wrapped around the optical alignment sleeve and two optical fiber coatings and having a hot-melt adhesive provided therein.