1. A speech processing apparatus, comprising: an entity extracting unit to extract entity information by extracting input speech entity information from input speech and extracting a respective upper entity from a respective same domain as the input speech entity information; a focus determination unit to determine a focus of the input speech using the extracted input speech entity information requiring a response; a mapping unit to map lower domain entities, of the domain, corresponding to the focus with the extracted input speech entity information; and a recognition unit to recognize a result of arranging the extracted input speech entity information according to semantic association among domain entities, of the domain, as the input speech, wherein the upper entity is a hierarchically higher entity, within the domain, than the lower domain entities, the semantic association among domain entities is preset, and entity portions within the extracted input speech entity information are semantically associated with one another.