1. A machine translation device that translates a first language sentence into a second language sentence, the machine translation device comprising: a translation unit configured to translate the first language sentence or the second language sentence into a third language sentence; and a second language translated sentence output unit configured to output a second language sentence corresponding to the first language sentence using a search result obtained by searching a database that stores more example sentences of a third language than example sentences of a first language and a second language using the translated third language sentence as a search key.