The invention relates to an electromagnetic actuator with variable reluctance comprising a fixed ferromagnetic armature (3) comprising at least two concentric cylinders of revolution linked by a ring nut, at least one magnetizing winding (2) arranged between said cylinders, a ferromagnetic moving armature (4) guided in reciprocating translation movements relative to said fixed armature (3), with which it defines a magnetic circuit with an air gap (20), the dimension of which varies during reciprocating translation movements of the moving armature (4), wherein said fixed armature (3) comprises at least two series of slots, a first series of slots provided radially in said outer cylinder and extending over the entire height of said outer cylinder, and a second series of slots provided radially in said outer and inner cylinders and extending only over a major part of the height of said cylinders.