Disclosed is a method for efficiently producing an aminopeptidase. The method comprises the steps of: transforming host bacteria with an aminopeptidase gene and a neutral protease gene, or transforming part of the host bacteria with the aminopeptidase gene and transforming the other part of the host bacteria with the neutral protease gene; culturing the host bacteria transformed with the aminopeptidase gene and the neutral protease gene or a mixture of the host bacteria transformed with the aminopeptidase gene and the host bacteria transformed with the neutral protease gene in a culture medium to exhibit both aminopeptidase and neutral protease genes; and recovering produced aminopeptidase from the culture broth.
