A vertical wind turbine that includes a plurality of vertical vanes which is secured to a vertical vane axis so as to be rotatable independently of one another about a respective vane rotational axis and which are rotatably mounted about a vertical rotor rotational axis on a common circular path. A method for operating a vertical wind turbine, in which method pitch angles of vertical wind turbine vanes driven about a respective vertical vane axis are specified. The vertical wind turbine is operated in a particularly efficient and material-preserving manner by control of the pitch angles, at least in a partial load mode of the vertical wind turbine, such that the vanes rotate with a substantially constant tip-speed ratio.