Assembly provided with at least one shielded connector(2, 12, 17, 50) and a board (1), each shielded connector being connected to a predetermined side of said board (1) and being provided with at least one signal contact member (3) fitted in a hole (7) of the board (1), the connector having a shielded (61) to shield each signal contact member (3), wherein the board (1), except in area where connectors (2, 12, 17, 50) are fitted to the board (1), is provided with a first continuous electrically conductive layer (9) on one side and a second continuous electrically conductive layer (10) on the opposite side, each of the shielded connector housings being electrically connected to one of said layers (9, 10), in order to prevent electromagnetic radiation generated by any of said signal contact members (3) from propagating to the outside word.