A mass-transfer column consisting of one or more contact zones. The contact zones are exclusively provided with packings placed in prearranged locations. In the contact zones, optimal operating conditions for the packings are created over the entire height of the contact zones in order to achieve a minimal pressure loss at a concomitant high separating efficiency. This is done by implementing a suitable gradated adaptability of the packing to the vapor and liquid loads varying over the height of the contact zones.