A content is delivered in consideration of a terminal used by a user, an ambient environment of the user and the terminal, and the characteristics and preferences of the user. A content delivery server has an input/output unit for transmitting and receiving information between itself and a terminal, a content management unit for managing contents composed of modalities, and a control unit for controlling the input/output unit and the content management unit. The control unit obtains attribute information composed of terminal attribute information on an output interface at the terminal, environmental attribute information on the current ambient environment of the terminal, and user attribute information on the characteristics of the user, generates, based on the obtained attribute information, modality construction information for specifying the modalities of a content to be delivered to the terminal, determines, by using the modality construction information, a modality construction for the content to be delivered which is under the management of the content management unit, and delivers the content composed of the determined modalitis to the terminal via the input/output unit.