The invention relates to a rotating device and a method for rotating an object suspended on a suspension. The rotating device can be attached to the suspension, for example to a crane hook, and comprises at least one motor (34), the motor shaft of which is oriented substantially vertically in the suspended state and can be connected to the suspended object, whereas the motor housing of the motor is connected to a rotatable rotational body. The rotational body (21) is rigidly connected to an energy store (35) and the axis (46) of the motor shaft substantially coincides with a main axis of inertia of the rotational body. In order to obtain the largest possible moment of inertia of the rotational body, the main part of the mass of the energy store (35) is accommodated in an outer area in relation to the radial extent R in the rotational body.