Abstract: A combustion chamber for a gas turbine engine has a wall which is provided with rows of apertures. The apertures are arranged so that the axes of the apertures form an angle of between 25.degree. and 35.degree. with respect to the inner surface of the wall. The apertures have a first cylindircal portion and a second divergent portion to produce fan shaped apertures. An upstream portion of the wall has apertures arranged in axially spaced groups, each of which has three rows of apertures and a downstream portion of the wall has apertures arranged in axially spaced groups, each of which has two rows of apertures. The axes of adjacent apertures in each row are spaced apart by at least three times the diameter of the cylindrical portion. The apertures produce effective film cooling of the wall using less cooling air than conventional cooling rings. The apertures may be arranged locally to cope with hot spots.