A memory card, memory card communication control method, electronic device, and wireless communication system are provided. The memory card can be used when inserted into an electronic device on which driver software cannot be installed, and can be inserted into an electronic device in the same manner as an existing memory card. Data is read from a flash memory in compliance with a data transmission request from a data reader. Upon receipt of a bit string of the data read from the flash memory, a signal processing section exercises on/off control over an antenna switch in accordance with the bit string, changes a load impedance of an antenna, generates a reflected wave by modulating an unmodulated carrier, which is transmitted to the antenna from the outside and uses the reflected wave to transmit the data to the data reader.