A communication device is connectable to a terminal device, which can perform a data communication with the communication device. The communication device is capable of receiving data through another communication device via a communication network. The communication device may include a data storing system that stores data received from the other communication device through the communication network, a data transmitting system that transmits the data stored in the data storing system, a data counting system that counts the number of pieces of data stored in the data storing system and have not yet been transmitted to the terminal device, and an indicating system that indicates the number of pieces of data counted by the data counting system.