A separator having a separator housing, a separator wheel arranged inside the separator housing and having an axis of rotation (X), and a guide vane assembly arranged in the separator housing, an annular space being provided between the guide vane assembly and the separator housing radially (R) perpendicular to the axis of rotation (X) and a separation zone being provided between the guide vane assembly and the separator wheel, and the guide vane assembly having a plurality of vertical guide vanes. In order to increase separation performance, at least one deflecting element is arranged between at least two adjacent vertical guide vanes and has at least one downward-pointing curved and/or bent portion.