A probe card for a testing apparatus of electronic devices comprises at least one testing head housing a plurality of contact probes, each contact probe having at least one contact tip abutting onto contact pads of a device under test, as well as at least one space transformer realizing a spatial transformation of the distances between contact pads made on its opposite sides and connected by means of suitable conductive tracks or planes, as well as a plurality of filtering capacitors provided between the space transformer and a PCB, which comprises direct conductive tracks or planes contacting conductive portions of the filtering capacitors.