EXPANSION GATE

PROBLEM TO BE SOLVED: To provide an expansion gate which prevents a guide rail from obstructing passing of a person or a vehicle and allows an expansion door to be rotationally housed when the expansion door is contracted.SOLUTION: The expansion gate comprises gate posts 1a and 1b, an expansion door 2 freely horizontally turnably connected to the gate post 1b, and a guide rail 3 buried under a ground surface G. The expansion door 2 includes a guide member 39 which is freely engaged and disengaged with/from the guide rail 3 by an operation of an operation part 4. The guide rail 3 is provided in an expanding direction of the expansion door 2 from the vicinity of a root of the gate post 1b, has a retaining part 6 for limiting detachment of the guide member 39, and has a part 3b without the retaining part on a suspension origin side.