The communication device includes: a communication control section which periodically causes a radio communication module to establish a connection to the server; a data reception and transmission instructing section which instructs the communication control section to obtain files and directory information stored in the server when the connection is established, and stores the files and the directory information in memories; and an emulation processing section which notifies, when the communication device is coupled to the computer, the computer that the communication device is a mass storage class device, submits the directory information stored in the memories to the computer, refers, when designation of a file contained in the directory information is accepted from the computer, to the directory information to read the file from the memories, and sends the file to the computer.