What kind of product to use to remove a black spots from upper bottom of “Staub”pot?

Regular baking soda usually works for me.

Hi Irina! We suggest trying something like Bar Keepers Friend--just be sure to use a soft sponge so that you don't accidentally chip the enamel. If you have any trouble, feel free to write us at [email protected] (sending a photo that illustrates the issue is always helpful, too). Happy to see what we can do!