Proposed are a method and an apparatus for receiving a PPDU in a wireless LAN system. Specifically, a receiving STA receives a PPDU from a transmitting STA via broadband communication and decodes the PPDU. The PPDU is received on the basis of an OFDMA scheme. The PPDU includes a first signal field. The first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband communication. The first information consists of a 4-bit bitmap for the 80 MHz band.