The invention relates to an electromagnetic actuating unit (10) of a hydraulic directional valve (9) having an armature (18) which is arranged such that it can be axially displaced within an armature space (30) and having a pole core (29) which is arranged in a receptacle (27a) and delimits the armature space (30) in a movement direction of the armature (18). Means are proposed for avoiding deposits on a guide face of the armature (18), as a result of which the dynamics and the response behaviour of the actuating unit (10) are increased and hysteresis effects and the risk of a functional disruption of the actuating unit are minimized.