Abstract: An air supply arrangement for air flow plates (5) of electrochemical cells (3) within a fuel cell stack (1). Each air flow plate (5) has a gas exchange volume (19). A common air supply pipe (11) supplies air to the air flow plates (5). There is an air supply region (35) and a separate air distribution conduit (15) for each air flow plate (5). Each air distribution conduit (15) provides an air header volume (43) and has an inlet and an outlet. The common air supply pipe (11) is connected to each air supply region (35) and each air supply region (35) is connected to the inlet of each air distribution conduit (15). The outlet of each air distribution conduit (15) is connected to a gas exchange volume (19) and each gas exchange volume (19) extends across the width of the associated air flow plate (5).