The present invention relates to a station (hereinafter, ‘STA’) operation method and apparatus in a TV whitespace. In a TVWS band, when an STA operating as an unlicensed device with permission to operate in an available channel not used by a licensed device needs to operate in the TVWS band by acquiring information on the available channel, the STA transmits an available channel information request message to a device having database information; receives, from the device having database information, an ACK message for the available channel information that includes (a) identification information on an available channel, (b) information on the maximum allowable power level in the available channel, and (c) information on valid time of the available channel; and transmits/receives a signal using the information of (a), (b) and (c), i.e., using the maximum allowable power level within the valid time in the available channel.