PURPOSE: To easily make a source sentence correspondent to a translated sentence by deciding the character size of the source sentence to be outputted according to a translated result and a character size table, and unifying the sentence position relation of the translated sentence with the source sentence.

CONSTITUTION: When translating the source sentence inputted from an input means 1, a translating means 3 utilizes a dictionary 4 and a grammatical rule part 5. A character size table 7 describes the character size of the translated sentence and according to the translated result of the translating means 3 and the character size table 7, a translated sentence character size deciding means 8 decides the character size of the translated sentence to be outputted. Then, an output means 6 outputs the correspondent translated sentence at the same position corresponding to the original coordinate position of the source sentence. Thus, the document format of the source sentence can be reflected on the translated sentence by a comparatively simple processing together with the sentence of the source sentence without executing the complicated analysis of the document format, the translated sentence can be easily correspondent to the source sentence, and the satisfactory translated result can be obtained without damaging the image of the source sentence.