Abstract: An electromagnetic actuator of an electrical contact includes: a stationary portion including at least one coil generating a magnetic field centered on a longitudinal axis; at least one core concentrating magnetic flux, installed within the coil, and including a plate spreading the magnetic flux and defining an active surface perpendicular to the longitudinal axis, and at least one element returning magnetic flux; an armature translationally movable along the longitudinal axis and relative to the stationary portion between first and second positions, by a force induced by the magnetic field; and at least one device returning the armature elastically to a predetermined position of the first position or second position. The spreading plate includes at least one rib closing magnetic field lines between the spreading plate and the armature, protruding relative to the active surface on the armature side and housed on one edge of the spreading plate.