The present invention is for transmitting capability information of a user equipment (UE), and a method of operating an electronic device according to various embodiments may comprise receiving system information from a cell of a first radio access technology (RAT); generating a message selectively including capability information of the electronic device for the second RAT according to whether the system information includes information about a cell of a second RAT different from the first RAT; and transmitting the message to the cell of the first RAT. In addition, various embodiments are possible.