The present invention provides, as an enzyme which can be used for enzyme replacement therapy for Fabry disease, a protein having α-galactosidase activity, which shows no allergic adverse side effect, shows a high stability in blood, and can be easily incorporated into a cell of an affected organ. The protein of the present invention is a protein which has acquired α-galactosidase activity by changing the structure of the active site of wild-type human α-N-acetylgalactosaminidase.