The invention relates to a metering valve (1) for controlling a gaseous medium, in particular hydrogen, comprising a valve housing (2), wherein an interior space (3) is formed in the valve housing (2). A reciprocating closing element (10) is arranged in the interior space (3), which interacts with a valve seat (37) for opening or closing at least one passage channel (25). Furthermore, the metering valve (1) comprises a nozzle (11), the at least one passage channel (25) being formed in the nozzle (11) and the passage channel (25) having a circular-cylindrical portion.