A copper foil with a blackened surface or layer wherein one or both surfaces of a copper foil is subject to black treatment, and having a color difference .DELTA.L*.ltoreq.-70 and chroma C*.ltoreq.15 of a black-treated surface when measured by a color difference meter represented by black; .DELTA.L*=-100, white; .DELTA.L*=0. The copper foil with a blackened surface or layer is especially useful for a plasma display panel (PDP) and has superior shielding characteristics of effectively shielding electromagnetic waves, near infrared rays, stray light, outside light and the like, has sufficient contrast, has a deep blackened color, is able to limit the reflected light of incoming light from the outside and reflected light of outgoing light from a plasma display panel, and has superior etching characteristics.