When a searching apparatus accepts a search condition including a logical condition formed of variables, transition table is created by using a BDD method. In the transition table, a combination of a bit string indicative of true or false of a variable at each level for arriving from a starting-point variable to an arrival variable and the starting-point variable is associated with the arrival variable. Then, a true/false decision on the search condition of the search target data is made by, with an arrival variable of a transition destination being taken as the starting-point variable, extracting a bit string of a predetermined number of digits from the starting-point variable from among logical bit strings of the search target data and specifying the arrival variable as the transition destination based on the combination and the transition table.