An apparatus for steam reforming includes a reactor, a condensate separator, a condensate stripper, and a steam boiler. The reactor produces hydrogen and is connected to the condensate separator such that a gas mixture is conducted from the reactor into the condensate separator. The condensate separator and the condensate stripper are connected so that condensate separated out in the condensate separator is conducted into the condensate stripper. The condensate separator and the steam boiler are connected such that cleaned condensate can be conducted into the steam boiler. The steam boiler is connected to the reactor and to the condensate stripper in a steam-conducting manner. The boiler water feed line of the steam boiler is connectable to the condensate stripper in a liquid-conducting manner. A supply from the boiler water feed line is at a same location of the condensate stripper as a supply of the condensate from the condensate separator.