Disclosed are: enzymes involved in the synthesis of equol; genes respectively encoding the enzymes; and a method for producing equol or an intermediate thereof by using the enzymes. Specifically disclosed are: a dihydrodaidzein synthase, a tetrahydrodaidzein synthase, and an equol synthase; genes respectively encoding the synthases; and a method for synthesizing dihydrodaidzein, tetrahydrodaidzein and/or equol by using the enzymes.
