A communication apparatus of a wireless LAN complying with the IEEE802.11 standard series determines, by executing CCA, whether a signal can be transmitted in a frequency channel to be used, transmits RTS in response to determination that the signal can be transmitted in the frequency channel, transmits data to a partner apparatus in a case where CTS is received from the partner apparatus in response to the RTS, and controls to use, in a case where the RTS is transmitted during a predetermined period after the communication apparatus shifts from a first state in which a signal cannot be received to a second state in which a signal can be received in the frequency channel, second transmission power lower than first transmission power used in a case where the RTS is transmitted during a period different from the predetermined period.