Disclosed are an apparatus and a method of calculating available channels considering a priority in a TVWS. An apparatus for calculating available channels considering a priority in a TVWS according to the present invention includes: a communication module configured to receive a request for information on usable available channels from a TV Band Device (TVBD); an available channel calculation unit configured to calculate one or more available channels usable by the TVBD based on one or more predetermined reference parameters according to the request; a priority assignment unit configured to assign a priority to each of the calculated available channels, generate an available channel list including the available channels to which the priorities are assigned, and provide the TVBD with the generated available channel list; and a database configured to store the available channels, to which the priorities are assigned, calculated for each TVBD.