To make a post for saddle or handle foldable in a single operation by providing a folding post formed of upper and lower posts connected to each other in such a manner as to be capable of rising and falling, and folding through a hinge, and locking the raised state of the upper and lower posts by toggle lock action.

In the raised state of a saddle post, the lower end surface of a lower post 2 makes contact with a contact surface 20 on the upper surface of a lower hinge 3, and the lower surface of an upper hinge 6 makes contact with a contact surface 21 on the upper end of the lower post 2 to lay the lower post 2 and the upper post in the same axial state, whereby the falling is regulated. In a lock mechanism, at this time, a pin 16 part for connecting a grip 14 to a link 17 is situated on the upper hinge 6 side, and a pin 19 part for connecting a rod 12 to the link 17 is situated on the upper end of a guide rail to impart a tensile force between fixed pins 13, 15, and the locked state is attained by toggle lock action. When the saddle post is folded, the pin 16 is displaced to the outside of the pin 19 to release the constraint of falling.