Consecutively hydrolyzes alpha(1-4) glycosidic bonds from the non-reducing ends of starch, resulting in the production of glucose. It also has a limited ability to produce glucose through the hydrolysis of amylopectin alpha(1-6) linkages. Hydrolysis of terminal (1->4)-linked alpha-D-glucose residues successively from non-reducing ends of the chains with release of beta-D-glucose. Expressed in presence of arabinose, cellobiose, fructose, glucose, glycerol, maltose, pullulan, soluble starch, or xylose. Belongs to the glycosyl hydrolase 15 family.