Provided are two types of translation engines. One of the translation engines translates a text written in a source language X into an intermediate language C, and the other translates the intermediate language C into a target language Y. The X-C translation engine translates an original text written in the source language X into a text in a predetermined intermediate language C as well as acquires and adds annotations obtained by this translation to the translated text written in the intermediate language C. The C-Y translation engine references annotations, which are obtained by the X-C translation engine and added to the text in the intermediate language C, and translates the text in the intermediate language into a text in the target language Y sentence.