A data reader can read data regardless of the position of a radio IC tag. The data reader reads data at a separate position from a radio IC tag provided with a storage unit storing data and a communicating antenna for transmitting the data stored in the storage unit, and includes a reader/writer for generating a modulated signal by modulating a carrier wave and a plurality of antenna units for transmitting radio waves for a read for communicating data with a storage medium by radiating the modulated signal into the air. The reader/writer includes a phase adjustment circuit for changing the phase of a carrier wave. |