An apparatus for providing an interface customized to contents among a plurality of contents is disclosed. The apparatus includes a contents provider configured to receive, from a first device, user information of the first device and a content request signal that requests the contents among the plurality of contents, and provide the requested contents to the first device based on the received user information of the first device, an interface request receiver configured to receive, from a second device, user information of the second device and an interface request signal that requests interface data, and an interface data provider configured to authenticate the second device by using both the user information of the first device and the user information of the second device, and provide interface data corresponding to the provided contents to the second device if the second device is authenticated.