A safety and arming device for an instant impact point fuse for a gyratory projectile and a fuse equipped with such a device. The device includes a rotor carrying a primer held in a safe, non-aligned position with respect to a striker by a sleeve pressed against a flat spot of the rotor. The device also includes a flyweight that, when subjected to the longitudinal acceleration resulting from the shot, exerts a pushing force on a first end of at least one lever, the second end of the at least one lever being located below a collar of the sleeve. The pushing force of the flyweight causes the lever(s) to pivot about a pivot point, the pivoting of the lever then separates the sleeve from the flat spot of the rotor permanently, releasing the rotor.