The invention relates to a method for mounting a wind turbine for generating electric current. Said wind turbine comprises a tower (26), a nacelle (41) (machine housing) equipped with an electric generator, and a blade rotor for mechanically driving the generator. After the tower is erected, the nacelle and the blade rotor or essential parts of these two structures are hoisted by a hoisting apparatus to the height of the tower and are then mounted. According to the invention, a hoisting apparatus is used for hoisting at least the heaviest part of the wind turbine to be mounted. Said hoisting apparatus is supported on the tower in order to ensure a sufficient level of stability for the respective hoisting process. The invention also relates to a device for carrying out the method. The boom (4) of the crane (1) is stabilized with the aid of a support fastened to the tower or a heavy lift auxiliary crane (28) is fastened to the upper end of the tower.