The present invention provides a portable electronic device which can achieve a further improvement in operability. When operations are detected by a plurality of different operation detecting units within a predetermined time interval, a controlling unit receives as input the letters assigned to each of the plurality of different operation detecting units that detect the operations, and performs predetermined processing on data related to the letters inputted. On the other hand, when operations are detected by a plurality of different operation detecting units outside a predetermined time interval, the controlling unit receives as input the letters assigned to each of the plurality of different operation detecting units that detect the operations, and does not perform predetermined processing on data related to the letters inputted.