The present invention provides a 1-thio-D-glucitol compound ofthe following formula, which shows the action of inhibitingthe activity of SGLT2, a pharmaceutically acceptable salt ofthe compound, or a hydrate of the compound or the salt； and apharmaceutical comprising such a compound as an activeingredient, especially, a pharmaceutical for preventing ortreating diabetes, diabetes-related disease, or diabeticcomplication. The invention also provides a method forproducing the 1-thio-D-glucitol compound and its intermediate.(see above formula)
