The invention relates to a discharge tube comprising an isolator tube with an internal surface and an external surface, an internal electrode consisting of a flexible flat material, which rests on the internal surface, an external electrode, which rests on the external surface, a spring element comprising at least one metal wire, which rests on at least part of the length of the internal electrode, causing the latter to impinge on the internal surface. The discharge tube has a low noise emission during operation and the components of said tube can be easily dismantled.