On-load tap-changer for uninterrupted advanced retard switch between winding taps (N 1,...N J,..., N N) of a tap-change transformer, comprising: - a change-over selector for powerless preselection to a selected winding tap (N J); - a diverter switch for the actual diverter switch operation from the previous winding tap (N J-1) to the preselected winding tap (N J), the diverter switch having a first load branch (5.1) and a second load branch (5.2); - the first load branch (5.1) of the diverter switch comprises a first vacuum interrupter (6.1) and a second vacuum interrupter (6.2), - the second load branch (5.2) of the diverter switch comprises a first vacuum interrupter (7.1) and a second vacuum interrupter (7.2), wherein - each vacuum interrupter (6.1, 6.2, 7.1, 7.2) has a moving contact and a fixed contact, and - each vacuum interrupter (6.1, 6.2, 7.1, 7.2) can assume an open state, in which the moving contact and the fixed contact do not touch each other, and a closed state, in which the moving contact and the fixed contact touch each other at at least one contact point, wherein - a spherical region is defined by the contact point of the fixed contact and the moving contact of each vacuum interrupter (6.1, 6.2, 7.1, 7.2); and - the vacuum interrupters (6.1, 6.2, 7.1, 7.2) of the diverter switch are arranged in such a way that current-carrying parts of the diverter switch are arranged outside the defined area, - the first load branch (5.1) electrically connects a winding tap (N J) via a series connection of the first vacuum interrupter (6.1) and the second vacuum interrupter (6.2) of the first load branch (5.1) to a load leakage line, - the second load branch (5.2) electrically connects a respective winding tap (N J+1) to the load leakage via a series connection of the first vacuum interrupter (7.1) and the second vacuum interrupter (7.2) of the second load branch (5.2), characterized in that - a first mechanical switching contact (18.1) is arranged between the second vacuum interrupter (6.2) of the first load branch (5.1) and the load arrester; and - a second mechanical switching contact (18.2) is arranged between the second vacuum interrupter (7.2) of the second load branch (5.2) and the load arrester; - the spherical region around the point of contact has a radius of at least 80 mm and at most 200 mm. - a change-over selector for powerless preselection to a selected winding tap (N J); - a diverter switch for the actual diverter switch operation from the previous winding tap (N J-1) to the preselected winding tap (N J), the diverter switch having a first load branch (5.1) and a second load branch (5.2); - the first load branch (5.1) of the diverter switch comprises a first vacuum interrupter (6.1) and a second vacuum interrupter (6.2), - the second load branch (5.2) of the diverter switch comprises a first vacuum interrupter (7.1) and a second vacuum interrupter (7.2), - each vacuum interrupter (6.1, 6.2, 7.1, 7.2) has a moving contact and a fixed contact, and - each vacuum interrupter (6.1, 6.2, 7.1, 7.2) can assume an open state, in which the moving contact and the fixed contact do not touch each other, and a closed state, in which the moving contact and the fixed contact touch each other at at least one contact point, - a spherical region is defined by the contact point of the fixed contact and the moving contact of each vacuum interrupter (6.1, 6.2, 7.1, 7.2); and - the vacuum interrupters (6.1, 6.2, 7.1, 7.2) of the diverter switch are arranged in such a way that current-carrying parts of the diverter switch are arranged outside the defined area, - the first load branch (5.1) electrically connects a winding tap (N J) via a series connection of the first vacuum interrupter (6.1) and the second vacuum interrupter (6.2) of the first load branch (5.1) to a load leakage line, - the second load branch (5.2) electrically connects a respective winding tap (N J+1) to the load leakage via a series connection of the first vacuum interrupter (7.1) and the second vacuum interrupter (7.2) of the second load branch (5.2), characterized in that - a first mechanical switching contact (18.1) is arranged between the second vacuum interrupter (6.2) of the first load branch (5.1) and the load arrester; and - a second mechanical switching contact (18.2) is arranged between the second vacuum interrupter (7.2) of the second load branch (5.2) and the load arrester; - the spherical region around the point of contact has a radius of at least 80 mm and at most 200 mm.