1. An RDF (Resource Description Framework) network construction device using an ontology schema, comprising: an ontology schema storing module that stores an ontology schema defining a relationship system between concepts; a class managing module that connects and stores, in a set, authority data composed of classes, terms classified by the classes, identifiers of the terms, representative terms, and identifier of the representative terms; a mining rule managing module that connects and stores, in a set, a property of the ontology schema, one mining pattern corresponding to the properties, and one or more RDF triples corresponding to the mining patterns; a mining pattern creating module that is linked with the class managing module, recognizes terms from an input text document and represents the terms into corresponding classes and properties representing relationships between classes, and converts the text document, which represents the classes into properties, into a mining pattern; and an RDF triple creating module that is linked with the mining rule managing module and creates an RDF triple by comparing the mining pattern stored in the mining rule managing module with the mining pattern of the text document, wherein the class of the class managing module is set by a key value and the property of the mining rule managing module is set by a key value.