There is provided a reductase characterized by
(i) an amino acid sequence of SEQ ID NO:1 having a substitution at amino
acid position 54 or 104 or at both of the amino acid positions 54 and
104, or
(ii) an amino acid sequence defined in (a) having further deletion,
substitution, or addition of an amino acid or acids and the like, which
reductase is provided with good heat stability and selectivity.