The invention relates to a proportional valve (1) for controlling a gaseous medium, in particular hydrogen, comprising a valve housing (2), in which a closing element (10) arranged therein interacts with a valve seat (19) in order to open and close at least one passage opening (18). Furthermore, an armature device (25), which is operatively connected to the closing element (10), and an electromagnet (26) are provided, by means of which electromagnet a magnetic force can be produced on the armature device (25) and the armature device (25) can move reciprocatingly along a longitudinal axis (40) of the proportional valve (1). Moreover, the electromagnet (26) comprises an inner pole (14), an outer pole (13) and a solenoid coil (12) and the armature device (25) composes an armature (8). The valve housing (2) and the inner pole (14) are magnetically connected to each other by means of a magnetic choke point (20). The magnetic choke point (20) is formed in an axial region of extent of the armature (8). Furthermore, the inner pole (14) has a cavity (21) having a cavity edge (35). The armature (8) plunges in said cavity (21) during the reciprocating motion of said armature. In a closed position of the proportional valve (1), an end face (33) of the armature (8) lies at the same height as the cavity edge (35) of the cavity (21) with respect to the longitudinal axis (40), the cavity edge (35) forming the end of the magnetic choke point (20).