1. A document processing apparatus comprising: first word extracting means for extracting a first word from document data; preceding/subsequent word extracting means for extracting, from the document data, a second word that is one of a preceding word and a subsequent word of the first word; keyword extracting means for extracting a keyword of the document data, based on a frequency of occurrence of the first word, wherein said keyword extracting means includes word counting means for counting a number of occurrences of each word, other than unnecessary words which are pre-excluded from being keywords, in the document data, said keyword extracting means extracting a word having a high number of occurrences, counted by said word counting means, as the keyword; and translation means for translating the keyword into a predetermined language by referring to a dictionary in a process that considers a meaning of the first and second words existing together in the document data.