Apparatus for the controlled supply of a compressible working fluid

A device for controlled supply of a compressible operating medium from a main supply line (3) to at least two branching points (4) comprises a regulation device (5) mounted in the main supply line. Pressure regulation is achieved using an equalization body (7). The invention also relates to a corresponding fuel cell stack (1) with at least two fuel cells (2) and a method for operation of a fuel cell stack.