In this paper the new spectral method of the variable ordering in the Binary Decision Diagram (BDD) is introduced. The problem to find the best order is defined as NP-hard, and optimal solution can not be finding because optimizing algorithm is running in O(n!2ⁿ) time, and calculations can not be done for the large n. Such complexity was obviously improved in many algorithms but as will be demonstrated in this paper size of the BDD can be additionally reduced. Performed results with another representative methods have been compared.