The present invention is directed to a shielding device of a double-sided printed substrate used in a circuit for processing a high frequency signal such as a television tuner circuit and the like, which is arranged such that a first grounding conductor film (12a) is formed on one side of the substrate (11), a second grounding conductor film (12b) is formed on the other side of the substrate (11), both the conductor films (12a, 12b) are connected by a through-hole conductor (15b), an opening portion of a through hole (15a) at at least one side is covered and closed by a solder resist (16), and the shielding plate (13) is mounted on the conductor film (12a) on the one side and both members are soldered. In particular, when a ceramic substrate is used as the substrate (11), it is arranged so as to obtain reliable soldering and satisfactory shielding effects while ensuring the strength thereof.