The invention relates to an improved escapement mechanism (100) comprising a pallet fork (1) having two pallets (10A; 10B), the resting surface (21 A; 21 B) of each pallet having an elliptical section with an axis of symmetry merged with a pivot axis of said pallet fork (1). The escapement mechanism also comprises restoring or repulsing means (40) co-operating with a fork rod (14) and/or arms (11 A; 11 B) of said pallet fork (1). Said restoring or repulsing means (40) are either electrostatic or mechanical elastic and comprise two springs (41 A; 41 B) arranged at the end of travel of said arms (11 A; 11 B) in such a way that a single arm co-operates with a single spring at a given moment, and/or they comprise a spring (42) co-operating with a groove or with a finger (24) of said fork rod (14).