PURPOSE: To provide a translator which obtains translations of high quality and reduces the labor of post-editing by setting the most suitable dictionary to be in the highest priority order in accordance with a document to be translated to perform the translation processing.

CONSTITUTION: When the dictionary selection processing is started, a list of available expert dictionaries and user dictionaries is displayed (S410), and the flag value indicating the priority order is set to 0 (S420). Dictionaries are successively selected by a user, and the flag value is incremented at each time of dictionary selection and is stored correspondingly to the selected dictionary (S440 and S450). The priority order is higher as the flag value is smaller. When translated words in the same part of speech are extracted from plural dictionaries by retrieval of dictionaries, only the translated word extracted from the dictionary having the highest priority order is used.