A device interconnects two circuit boards each comprising electrical connection pads, and which are respectively placed in two cavities. The device includes intercavity microwave screening means. The device also comprises several electrical conductors that pass through the device from end to end and that are not soldered, the two ends of which conductors are respectively intended to make direct contact with the connection pads of the two circuit boards; and mechanical means for holding the two circuit boards against the device, at either end of the latter. The screening means are provided by a microwave absorber in contact with each conductor and surrounding it over all or some of its length.