The invention relates to a commutation spark gap (1) comprising at least one first electrode and one second electrode, both electrically conducting, each comprising an arc zone placed opposite the arc zone of the other electrode, the electrodes being adapted to be linked to the terminals of a source of potential, characterized in that the spark gap (1) exhibits a general tubular shape, said first electrode (2) forming a cylindrical body (3) of the spark gap, open at its two ends, and said second electrode, termed the central electrode (4), cylindrical and co-axial with the first, extending along the axis of the spark gap at least from one end to the other of the cylindrical body (3).