controller 8 serves as an ic card control section for requesting a resume process upon detection of a ring signal from a public telephone line 10 a facsimile fax modem ic card 9 is an ic card having a facsimile transmission reception function and a modem function a power supply control unit 11 checks the remaining capacity of a battery 12 and performs charge control fig2 is a flow chart showing the resume process stored in the rom 2 for the cpu 1 this flow chart shows a process to be performed when a resume request ring signal occurs when the system is in the suspend state energy saving mode when a resume request occurs the resume process of step 2 shifts the system from the suspend state or energy saving mode in which the operation of the cpu is stopped and only refreshing of the ram 3 is being performed to the normal operation mode in which the cpu 1 is operative cpu 1 determines in step s3 whether a ring signal caused this resume request if yes in step s3 the flow advances to step s4 otherwise this process ends because the process is not a reception process of this embodiment in step.