To enable folding chairs to be stacked up in various states.

Stacking bars (15) are provided between front legs (2) and rear legs (3). A seat part (7) supported by the front legs (2) and rear legs (3) is revolvable from a horizontal state to an upright state. A seat back-cover (14) of the seat part (7) has an ear-shaped rest parts (20) able to place the stacking bars (15) and projecting from both sides. The rest parts (20) have stoppers (21) and ribs (22) for engaging with engaging parts of the stacking bars (15). The folding chair can be vertically stacked so that the stacking bars (15) are placed on the rest parts (20) as the seat part is kept horizontal or stacked so that the seat part is raised and lower edge of the backrest (5) is retracted to a recess part (32) of the back cover (14).