A connecting device for electrically connecting electrical lines to electrical contacts includes a flexible circuit board or printed circuit board, a base support, and a cover. The electrical lines or conductors are disposed on the flexible circuit board. The flexible circuit board has a contacting-making region, in which at least one electrical line is electrically connected to at least one electrical contact. The electrical contacts are disposed on the base support. The flexible circuit board is disposed between the base support and the cover and the base support and the cover form a sealed housing for the contacting-making region.