The present invention relates to a method for receiving a Physical Downlink Control Channel (PDCCH) by a user equipment (UE) in a wireless communication system to which a carrier aggregation scheme is applied. In particular, the method includes the steps of: monitoring the PDCCH during an On Duration within a discontinuous reception (DRX) cycle on a specific serving cell among at least two activated serving cells, and monitoring the PDCCH during an Active Time within the DRX cycle on all of the at least two serving cells based on the PDCCH being detected during the On Duration within the DRX cycle on the specific serving cell.