An electronic device and an electronic-device-operating method are provided. The electronic device includes an embedded subscriber identity module (eSIM) embedded in the electronic device, the eSIM storing a first profile associated with a first communication service, a physical subscriber identity module (pSIM) configured such that a SIM card is capable of being removably attached thereto or capable of being inserted thereinto, the pSIM storing a second profile associated with a second communication service, a communication processor configured to control the eSIM and the pSIM, and a processor. The processor is configured to receive a signal indicating switching from a dual standby mode to a single standby mode, control a local profile assistant in device (LPAd) configured to control the eSIM in response to reception of the signal, delete a task associated with the eSIM in response to completion of disabling the LPAd, request deactivating of a protocol stack corresponding to the eSIM in response to deleting the task, and reset the communication processor in response to deactivation of the protocol stack.