A portable electronic device and a method of controlling are disclosed, each of which is capable of efficiently selecting a communication processing unit. The portable electronic device includes: a first communication processing unit conforming to a first communication scheme; a second communication processing unit conforming to a second communication scheme; a third communication processing unit conforming to a third communication scheme; and a control unit. When data communication is performed, the control unit controls each processing unit so as to preferentially use the first communication processing unit, the second communication processing unit, and the third communication processing unit in this order. In a case in which a network is disconnected while data communication is being performed by the second communication processing unit, the control unit executes control so as to continue the data communication by the third communication processing unit.