A method of managing a multimedia database, comprising the following steps: - creating (402, 405) an identifier allocator agent for associating a unique reference (Id, Id c) with each multimedia document or element of a multimedia document (Di); - acquiring a multimedia document (Di) of heterogeneous content comprising information belonging to at least one of the following categories of type: image, video, sound, text, animated vector graphics; - indexing the multimedia document (Di), where indexing comprises: a1) analyzing the multimedia document to extract both homogeneous components each belonging to a category of the same type of content of the homogeneous components of the multimedia document, and also to extract relationships between said homogeneous components, the relationships between the homogeneous components being identified as a function of a graph of objects establishing the relationships between the different components of the document; b1) characterizing the content of each of the homogeneous components and establishing relationships between the elements of the content of each of said homogeneous components based on the semantic content thereof; c1) producing a composite signature combining the indices of each of the homogeneous components obtained during said content characterization, the previously identified relationships, and all of the previously acquired identifiers; - storing the indexed multimedia document together with its composite signature; and - searching a multimedia document (Di) as previously indexed and stored using a composite request, searching comprising: a2) analyzing the composite request to extract homogeneous requests referring to a category of a single type; b2) processing the homogeneous requests; c2) synthetizing results of processing homogeneous requests; d2) establishing a pertinence order for the results and presenting the results wherein the indexing step is made using at least an indexing agent comprising at least two subagents using specific processing modes of indexing with respect to elements of different types being part of a multimedia document, and wherein the searching step is made using at least a search agent comprising at least two subagents using specific processing modes of searching with respect to elements of different types being part of a multimedia document. - creating (402, 405) an identifier allocator agent for associating a unique reference (Id, Id c) with each multimedia document or element of a multimedia document (Di); - acquiring a multimedia document (Di) of heterogeneous content comprising information belonging to at least one of the following categories of type: image, video, sound, text, animated vector graphics; - indexing the multimedia document (Di), where indexing comprises: a1) analyzing the multimedia document to extract both homogeneous components each belonging to a category of the same type of content of the homogeneous components of the multimedia document, and also to extract relationships between said homogeneous components, the relationships between the homogeneous components being identified as a function of a graph of objects establishing the relationships between the different components of the document; b1) characterizing the content of each of the homogeneous components and establishing relationships between the elements of the content of each of said homogeneous components based on the semantic content thereof; c1) producing a composite signature combining the indices of each of the homogeneous components obtained during said content characterization, the previously identified relationships, and all of the previously acquired identifiers; a1) analyzing the multimedia document to extract both homogeneous components each belonging to a category of the same type of content of the homogeneous components of the multimedia document, and also to extract relationships between said homogeneous components, the relationships between the homogeneous components being identified as a function of a graph of objects establishing the relationships between the different components of the document; b1) characterizing the content of each of the homogeneous components and establishing relationships between the elements of the content of each of said homogeneous components based on the semantic content thereof; c1) producing a composite signature combining the indices of each of the homogeneous components obtained during said content characterization, the previously identified relationships, and all of the previously acquired identifiers; - storing the indexed multimedia document together with its composite signature; and - searching a multimedia document (Di) as previously indexed and stored using a composite request, searching comprising: a2) analyzing the composite request to extract homogeneous requests referring to a category of a single type; b2) processing the homogeneous requests; c2) synthetizing results of processing homogeneous requests; d2) establishing a pertinence order for the results and presenting the results a2) analyzing the composite request to extract homogeneous requests referring to a category of a single type; b2) processing the homogeneous requests; c2) synthetizing results of processing homogeneous requests; d2) establishing a pertinence order for the results and presenting the results