A method for operating a wind power installation which is connected to a network connection point of an electrical supply network and is intended to produce and feed electrical energy into the electrical supply network, wherein the electrical supply network has a network nominal frequency and is operated at a network frequency, and the wind power installation which comprises an electrical generator with a generator nominal power can be regulated on the basis of the network frequency, comprising the steps of: using the electrical generator to produce an electrical generator power for feeding into the electrical supply network, feeding the electrical generator power or a part of it into the electrical supply network as electrical feed-in power on the basis of the network frequency, wherein, in a first supporting stage, the electrical generator power is reduced on the basis of the network frequency in order to accordingly reduce the electrical feed-in power, and, in a second supporting stage, the electrical feed-in power is reduced such that the electrical feed-in power is less than the electrical generator power.