The present disclosure relates to a communication technique for convergence of a 5G communication system for supporting a higher data transmission rate beyond a 4G system with an IoT technology, and a system therefor. The present disclosure may be applied to an intelligent service (for example, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety-related service, etc.) on the basis of a 5G communication technology and an IoT-related technology. An operation method of an inter-antenna phase calibration device in a wireless communication system using an unlicensed band according to an embodiment of the present invention comprises the steps of: calculating a listen before talk (LBT) processing time while an LBT is being performed; selecting a calibration mode for calibrating an inter-antenna phase on the basis of the LBT processing time; and calibrating the inter-antenna phase according to the selected calibration mode.