The purpose of the present invention is to provide a novel protein that can be used for a variety of purposes and has saccharide oxidase activity. The present invention provides a protein having the following physicochemical properties. (1) Activity: oxidizes sugar to produce a sugar acid. (2) Substrate specificity: reacts with glucose, maltotriose, maltose, galactose, maltotetraose, lactose, and cellobiose. (3) [Glucose Km value]/[maltose Km value]
