A composite pane includes an outer pane and an inner pane that are joined to one another via a thermoplastic intermediate layer, wherein the composite pane has at least one functional film that contains at least one metal layer, and the thermoplastic intermediate layer is formed with at least one thermoplastic film that contains refractive-index-reducing agents and these refractive-index-reducing agents reduce the refractive index of the thermoplastic film by at least 0.05 in the optically visible range between 380 nm and 780 nm.