To provide a word searching device which accurately obtains necessary information with easy and few operations compared with a conventional document ranking search.

The word searching device is provided with a document storing part which stores a document group, an input part which inputs a word pair and a word, an output part which outputs a relative word group, and a control part which outputs the relative word group from the output part. The control part 3 prepares a function which stores the result of search using a document searching part 6 on the basis of the word pair stored in an input buffer 5 in a searching buffer 7; which stores the result of extraction using a relative word extraction part 8 on the basis of the document group stored in the searching buffer 7 in a relative word buffer 9; which stores the result of search using the document searching part 6 on the basis of the relative word group stored in the relative word buffer 9 and the word stored in the input buffer 5 in the searching buffer 7; which stores the result of extraction using the relative word extraction part 8 on the basis of the document group stored in the searching buffer 7 in the relative word buffer 9; and which outputs the relative word group stored in the relative word buffer 9 from an output part 2.