To provide an automatic folding gate which is automatically opened/closed by a driving means.

The automatic folding gate 1 has at least a first door body 11 rotatably supported by a gatepost 10, and a second door body 12 foldably connected to the first door body 11, and is comprised of a planetary chain wheel mechanism 2 consisting of (a) a first chain wheel 20, (b) a second chain wheel 21, and (c) a chain 22. The first chain wheel is irrotationally fixed to the gatepost 10. The second chain wheel is irrotationally fixed to a spindle 43 which is formed in one body with the second door body 12 and rotatably axially supported by a support portion formed on a side end of the first door body 11 facing the second face body, to thereby rotate together with the second door body 12. The chain connects the first and second chain wheels 20, 21 together. Thus by rotating the first door body 11 by the driving means 3 (a controller 32, a deceleration motor 30, a link 31), the first and second door bodies 11, 12 are automatically opened/closed in a folding manner.