Abstract: An apparatus for chemically treating the surfaces of printed circuit board work pieces (PCBWP's) includes a tank for holding a bath of the chemical treatment liquid. A receiving device is provided for receiving the PCBWP's from a conventional transport conveyor in a horizontal orientation, and immersing the PCBWP's into the bath in a substantially vertical orientation. A conveyor device in the tank is configured to hold the PCBWP's in the vertical orientation and to move them face-on through the liquid bath while a substantially uniform transverse flow of fresh liquid is provided between the work pieces. Another conveyor device receives the PCBWP's and elevates them out of the bath in the vertical orientation, subsequently returning them to a horizontal orientation for delivery to a conventional transport conveyor.