There is obtained a telephone set capable of preventing a noise generated by an operation of application software during voice communication from being sent to a speech counterpart. In a mobile telephone set, if a user operates activated application software other than voice communication related application software when the mobile telephone set is in voice communication with another telephone set via a communication network, the mobile telephone set requests hold of the voice communication from the communication network. This causes the voice communication to be held, thereby preventing a noise generated by the above operation from being sent to the another telephone set.