A device and a method of reducing high-frequency currents between the tip of the soldering iron and the circuit board are described. In one embodiment, a special EMI filter and a method of it implementation in soldering process is described. This device and this method of implementation provide significant reduction of high-frequency current to the sensitive components. Another embodiment describes an implementation of EMI-reducing filter inside the soldering iron. Yet other embodiments include implementation of EMI-reducing filter as a part of the solder station, of the vise holding the circuit board, of the solder spool holder and as a stand-alone device.