A mobile radio communication device can automatically initialize the mode of a SAM card (or the SAM function area of an IC card) after executing radio communication with an external radio communication apparatus. The mobile radio communication device transmits/receives data to/from an external radio communication apparatus located in an area that allows radio communication. In the mobile radio communication device, an IC card that receives power supply from a mobile radio communication device main-unit, that manages data transmitted/received to/from the external radio communication apparatus, and that manages a communication mode state of the mobile radio communication device is detachably connected to the mobile radio communication device main-unit. The mobile radio communication device further includes radio-signal strength determining means for determining whether or not a strength of radio signals received from the external radio communication apparatus is less than or equal to a preset threshold value, and IC-card-mode initializing means for resetting a mode of the IC card to an initial state when the radio-signal strength determining means determines that the strength of the radio signals is less than or equal to the threshold value.