The purpose of the present invention is to provide a remote operation system, user terminal and remote operation method which make it possible to eliminate the work of operating a terminal by a person carrying out a remote operation. The remote operation system according to the present invention is provided with: a user terminal (10) which comprises a server function unit for operating internal functions of the terminal in accordance with a remote operation; a support terminal (20) for remotely operating the user terminal (10); and a relay server (30) which comprises an access management unit for retaining an access timing used for starting remote operation of the user terminal (10) by the support terminal (20), and which accesses the user terminal (10) at the access timing. When the user terminal (10) is accessed by the relay server (30), the user terminal (10) activates the server function unit and notifies the support terminal (20) that the server function unit has been activated. When the support terminal (20) is notified of the activation of the server function unit, the support terminal (20) activates a remote operation application and remotely operates the user terminal (10).