In an organic memory which is included in a radio chip formed from a thin film, data are written to the organic memory by a signal inputted with a wired connection, and the data is read with a signal by radio transmission. A bit line and a word line which form the organic memory are each selected by a signal which specifies an address generated based on the signal inputted with a wired connection. A voltage is applied to a selected memory element. Thus writing is performed. Reading is performed by a clock signal or the like which are generated from a radio signal.