In an electronic device and an operation method of the electronic device according to various embodiments, the electronic device may comprise a first communication circuit supporting first cellular communication, a second communication circuit supporting second cellular communication, and a processor, wherein the processor is configured to: in a state of being connected to a network, release a connection of the first cellular communication in response to reception and/or transmission of a call connection request message; perform a connection of the second cellular communication or control the second communication circuit so as to maintain the connection of the second cellular communication; in response to termination of the call connection, determine whether to release the second cellular communication, on the basis of whether at least one condition is satisfied, the at least one condition including a condition related to whether system information receivable through the second cellular communication is received; and perform the connection of the first cellular communication on the basis of information for the connection of the first cellular communication, which is included in the system information. Various other embodiments are possible.