A method of controlling answering a call in a system including a service server, a plurality of mobile terminals including a sender terminal and a receiver terminal, and a network configured to allow a communication between the service server and the mobile terminals includes displaying, when receiving a call, an incoming call icon and an incoming call screen, which are set in advance at the sender terminal, on the receiver terminal, receiving, upon the incoming call icon being displayed, an input of a predetermined operation on the incoming call screen at the receiver terminal, and permitting answering the call based on the predetermined operation at the receiver terminal.