A combustion membrane (14, 14′) for a gas burner (2) forms a multilayer panel (22) including a gas-permeable diffuser layer (24) of a porous or fibrous solid material other than metal sheet, the diffuser layer (24) forming a combustion surface (25) facing an outer side (17), a support layer (26) formed by a metal sheet (32), arranged on an inner side (23) with respect to the diffuser layer (24), opposite to the combustion surface (25), and connected to the diffuser layer. The metal sheet has a pattern (27) of passage openings (28), a local deviating layer (29), bordering the support layer (26). Diverter flaps (30) bent transversely out of the support layer (26) and delimited by cutting or tearing edges (42) of the support layer metal sheet (32), form guide surfaces (31) oblique to a direction (40) orthogonal to an extension plane (41) of the multilayer panel (22).