Abstract: A curtain wall includes one or more mullion profiles and one or more transom profiles and panels which are mounted in the mullion profiles and in the transom profiles by their edges. The one or more mullion profiles extend vertically and are provided with an undercut groove on two opposite sides which has an access opening. The grooves form a rebate in which the rim of a panel is mounted. The undercut groove has an elongate cross section which is provided, at the one or several of the transverse ends, with a rounded section and/or which is free from roundings with a radius of less than 2 millimeters at one or several of the transverse ends.