An impingement cooled wall arrangement includes a flow diverter arranged in the cooling flow path between the cooled wall and a sleeve to divert a cross flow away from a second aperture. The flow diverter extends in downstream direction of the cross flow beyond the second aperture with a first leg extending along one side of the second aperture in downstream direction of the cross flow and a second leg extending along the other side of the second aperture. No impingement cooling aperture is arranged in a first convective cooling section of the wall between the upstream end and downstream end of the flow diverter outside the section shielded by the diverter.