To improve cooling performances of quenching gas in a gas blast switch comprising a gas channel connecting an arcing region to a gas storage chamber delimited by radially opposite inner and outer walls and axially opposite first and second end walls, a flow guiding radial wall extends in the gas storage chamber spaced from each wall delimiting the chamber, an opening of the gas channel into the gas storage chamber through the first end wall faces a space between the flow guiding radial wall and the inner wall, the outer wall includes a deflecting portion protruding in the gas storage chamber and facing the second end wall, and at least part of the deflecting portion is offset from the flow guiding radial wall in an axial direction oriented from the gas channel towards the gas storage chamber.