Disclosed are a method and an apparatus for active scanning in a wireless LAN. In the method for active scanning in the wireless LAN, a scanning STA, which has received from a different STA a first probe request frame, can start a probe timer and perform a clear channel assessment (CCA) for detecting a channel state of a receiving channel. When the channel state is not busy until the probe timer reaches a minimum channel time, the scanning STA transmits to an AP from the receiving channel a second probe request frame, and when the channel state is busy until the probe timer reaches the minimum channel time and the scanning STA does not receive a probe reply frame, which includes at least the same information expected to be received based on scanning information, the scanning STA can transmit to the AP from the receiving channel the second probe request frame