Abstract: The invention relates to a method of and a device for braking an asynchronous motor by applying a direct current to the field windings thereof. According to the invention, an AC voltage appearing at the outer terminals (4,6) of two mutually series-connected field windings (1,2) of the asynchronous motor acting as a generator is rectified and connected to a coil (19) of a braking current relay (28) immediately after the operating current of the motor has been switched out, whereby said braking current relay (28) picks up and a terminal (R) of a braking current source (R, N) is connected by contacts (20,21,22) of said braking current relay (28) through a semi-conductor (24) to an outer terminal (6) of said field windings (1,2) and through another semi-conductor (25) to another outer terminal (4) of said field windings (1,2), a terminal (5) common to said field windings (1,2) being connected through a braking current adjuster (26) to another terminal (N) of the braking current source (R, N).