1. A machine translating method for a source language PDF file in a machine translation device, the method comprising: extracting, by the machine translation device, source language text from the source language PDF file; analyzing, by the machine translation device, the source language text to classify the source language text into text paragraphs; classifying, by the machine translation device, the text paragraphs into body paragraphs and non-body paragraphs; selecting, by the machine translation device, a first body paragraph that is not contextually divided among the body paragraphs based on at least one of font information and paragraph information; testing, by the machine translation device, a paragraph of a second body paragraph other than the first body paragraph among the body paragraphs to extract start and end information of the paragraph; selecting, by the machine translation device, a contextually divided body paragraph based on the start and end information; restoring, by the machine translation device, the source language text by combining a contextually divided body paragraph in the source language text; and translating, by the machine translation device, the restored source language text into target language text.