The invention relates to a solenoid wherein a magnetic discontinuity is formed in the pole tube reducing the effective material thickness, such as by reducing the thickness, particularly the wall thickness of the magnetically active material, the front face of the armature facing the pole core and a bottom face in the interior of the pole tube at the pole core each have a contour allowing mutual axial overlapping. This enables advantageous influencing of the force-stroke characteristic curve of the solenoid with low production effort.