The invention presents a control arrangement of an electric motor (2) used with a frequency converter (1 ) as well as a method for controlling an electric motor used with a frequency converter. In the invention the frequency converter is fitted between the power source (3) and the electric motor (2). A rectifier (5, 18) that transmits the braking power of the motor is fitted to the intermediate circuit (8, 9) of the frequency converter. In the method according to the invention the intermediate circuit voltage (21) is regulated with a control (11) of the braking power according to the reference value (12) of intermediate circuit voltage.