Semiconductor device comprising - a semiconductor body extending in vertical direction between a top side and a bottom side, - a first main electrode on the top side and a second main electrode on the bottom side, - a gate electrode, - at least two trenches, namely a first-type trench and a second-type trench, each extending from the top side into the semiconductor body, wherein - the semiconductor body comprises - a drift region of a first conductivity type vertically between the top side and the bottom side, - at least two base regions, namely a first and a second base region, each of a second conductivity type and each arranged vertically between the drift region and the top side, - an injection region of the first conductivity type vertically spaced apart from the drift region by the first base region and adjoining the first base region, - the first base region, the first-type trench, the second base region and the second-type trench are arranged in this order one after the other in a first lateral direction, - the first main electrode is in electrical contact with the injection region, - the gate electrode extends into the first-type trench where it is separated from the semiconductor body by a gate insulation layer, - the second-type trench is free of the gate electrode, - the second base region comprises a plurality of laterally spaced contact areas, wherein the second base region is in electrical contact with the first main electrode in each of these contact areas, - the contact areas in the second base region are spaced apart from each other in a second lateral direction which is perpendicular to the first lateral direction, characterized in that - the distance between the first-type trench and the second-type trench measured in the first lateral direction varies when moving along the second lateral direction, - the distance between the first-type trench and the second-type trench is greater where a contact area is arranged between them and smaller where no contact area is arranged between them, and further characterized in that - the second-type trench extends deeper into the semiconductor body than the first-type trench. - a semiconductor body extending in vertical direction between a top side and a bottom side, - a first main electrode on the top side and a second main electrode on the bottom side, - a gate electrode, - at least two trenches, namely a first-type trench and a second-type trench, each extending from the top side into the semiconductor body, wherein - the semiconductor body comprises - a drift region of a first conductivity type vertically between the top side and the bottom side, - at least two base regions, namely a first and a second base region, each of a second conductivity type and each arranged vertically between the drift region and the top side, - an injection region of the first conductivity type vertically spaced apart from the drift region by the first base region and adjoining the first base region, - a drift region of a first conductivity type vertically between the top side and the bottom side, - at least two base regions, namely a first and a second base region, each of a second conductivity type and each arranged vertically between the drift region and the top side, - an injection region of the first conductivity type vertically spaced apart from the drift region by the first base region and adjoining the first base region, - the first base region, the first-type trench, the second base region and the second-type trench are arranged in this order one after the other in a first lateral direction, - the first main electrode is in electrical contact with the injection region, - the gate electrode extends into the first-type trench where it is separated from the semiconductor body by a gate insulation layer, - the second-type trench is free of the gate electrode, - the second base region comprises a plurality of laterally spaced contact areas, wherein the second base region is in electrical contact with the first main electrode in each of these contact areas, - the contact areas in the second base region are spaced apart from each other in a second lateral direction which is perpendicular to the first lateral direction, - the distance between the first-type trench and the second-type trench measured in the first lateral direction varies when moving along the second lateral direction, - the distance between the first-type trench and the second-type trench is greater where a contact area is arranged between them and smaller where no contact area is arranged between them, and - the second-type trench extends deeper into the semiconductor body than the first-type trench.