1. A machine translation apparatus comprising: a identification information detection unit that detects identification information identifiable to a designated object; a receiving unit that receives a source language sentence; a word dividing unit that divides the source language sentence into a plurality of first word by morphological analysis; a deixis detection unit that detects, from the first words, a deixis indicating the object directly; a correspondence setting unit that sets the identifiable information of the designated object and the deixis in correspondence with each other; a semantic class determining unit that determines a semantic class indicating a semantic attribute of the designated object based on the identifiable information of the designated object corresponding to the deixis; and a translation unit that translates the source language sentence where the deixis is attached with the semantic class of the designated object.