An object is to provide a portable radio communication apparatus which allows a user to easily view displayed contents when the apparatus is folded even in the nighttime or in a dark place, and which can extend the battery life. A second case 4 is connected to a first case 2 so as to be in open and closed positions with respect to the first case 2. A main display section 11 which is exposed when the second case 4 is in the open position, a sub-display section 12 which is exposed whether the second case 4 is in the open or closed position, a main illuminating device 23A which illuminates the main display section 11, and a sub-illuminating device 23B which illuminates the sub-display section 12 are provided. A driver 24 which selects a line to supply electric power for illumination to the main illuminating device 23A or the sub-illuminating device 23B, and a detecting switch 22 which detects whether the second case 4 is in the open or closed position, are also provided. A control section 25 is also provided which controls the driver 24, with reference to the detected result, to supply electric power to the main illuminating device 23A when the second case 4 is in the open position, and to supply electric power to the sub-illuminating device 23B when the second case 4 is in the closed position.