A vacuum interrupter (1) according to the present invention of parallel magnetic field electrode type comprising a pair of separatable arc electrodes (20) disposed within a vacuum vessel (4) and each provided on its back side with a conductive rod (7 or 8) extending outwardly of said vacuum vessel (4), coil electrodes (15) electrically connected between the associated arc electrode and rod for applying parallel magnetic fields (H, to H 4 ) to arc, and slits (24) formed in the arc electrodes for suppressing eddy currents of the arc electrodes resulting from said parallel fields (H, to H 4 ), wherein a reinforcement member (27) of an electric conductivity higher than a main surface portion (21) of the arc electrode is provided onto the back side of the arc electrode opposite to said main surface portion so that the resulting arc current flows uniformly through said reinforcement (27), whereby a higher interruption efficiency can be obtained for said vacuum interrupter.