To provide a technique for accurately and efficiently generating Boolean search formulas that serve as a basis of similarity search. A Boolean search formula generation apparatus according to the present invention establishes Boolean search formulas expressed in a standard sum of products form connecting products of search terms by a sum and evaluates the Boolean search formulas based on a recall and a precision. The Boolean search formula generation apparatus repeats connecting the products of the search terms with maximum evaluation values by a sum to establish a Boolean search formula.