To reduce an energy amount that should be absorbed by a rope by reducing a height from which an object falls.

This fall prevention device comprises: a first metal fitting 31; the lower side first passing part of a lower metal fitting 35 which is secured to a sign post 14 and allowing a first linear part 20d continuous to one end thereof fixed to the first metal fitting 31 to be inserted therethrough; a fixed side first passing part of a second metal fitting 32 allowing a second linear part 20e continuous to the first linear part 20d to be inserted therethrough; an upper side metal fitting 36 which is secured to the sign post 14 at the further upper side than the lower side metal fitting 35 and allowing a third linear part 20f continuous to the second linear part 20e to be inserted therethrough; a fixed side second passing part of the first metal fitting 31 allowing a fourth linear part 20g continuous to the third linear part 20f to be inserted therethrough; a lower side second passing part of the lower metal fitting 35 allowing a fifth linear part 20h continuous to the fourth linear part 20g to be inserted therethrough; and the second fixing part of the second metal fitting 32 capable of fixing one end of a wire rope 20 continuous to the fifth linear part 20h.