A micro-machined or micro-engraved safety and arming device for a pyrotechnic train of a projectile to which axial spin is imparted after firing, such device comprising a substrate onto which a shutter to break the pyrotechnic train is positioned, such shutter being mobile in translation on the substrate, device in which the train-breaking shutter is held immobile by at least two locks, a first lock, or axial acceleration lock, which is released further to the application of the acceleration communicated to the projectile during firing, and a second lock, device wherein the second lock is a centrifugal lock that is released further to the projectile being made to spin.