A battery saving method of controlling the display of a portable telephone is disclosed. The method comprises checking whether a user inputs a SEND key for a call origination to establish a call or an answering key in response to an incoming call; turning off the power supplied to the display when a call is set up according to the SEND key or the answering key; and, turning on the power supplied to the display when the call is terminated. Further, the display is turned off after a predetermined period of time has elapsed after the SEND key or the answering key is activated.