A device in an electrostatic precipitator for suspending, controlling and rapping one or more collecting electrodes arranged essentially vertically in one or more substantially parallel rows includes, for each row, a substantially horizontally oriented carrier element, to which the upper ends of the collecting electrodes are attached, connecting elements which connect the carrier element to the casing of the electrostatic precipitator, a control arrangement for controlling the motion of each row of collecting electrodes in the transverse and/or longitudinal direction of the electrostatic precipitator, and a rapping mechanism for rapping the collecting electrodes of each row. The rapping mechanism includes a rapping device, such as a rapping hammer, and an anvil connected to the carrier element. The carrier element of each row is separately suspended by means of the connecting elements, thereby permitting, during rapping, a minimum horizontal pivoting motion restricted to each row of collecting electrodes and occurring in the longitudinal direction of the electrostatic precipitator.