A cell phone 1 is characterized by having a problem determination storage 3 for storing problem finding information for determining whether there is a problem in received data received by a radio communicator 2, in correspondence to a fixed message, and for storing an arbitrary message available for arbitrary correspondence to the problem finding information; an arbitrary message determination processor 5 for determining whether an arbitrary message is stored in correspondence to the problem finding information in the problem determination storage 3, when it is determined that there is a problem in the received data; and an operation controller 6 for displaying the arbitrary message when the arbitrary message determination processor 5 determines that the arbitrary message is stored, and for displaying the fixed message stored in the problem determination storage 3, when it is determined that no arbitrary message is stored.