Water is placed in the lower container, approximately 3-oz. per cup. Also in the lower container, is a basket that holds the finely ground espresso coffee, approximately 1-2  full rounded teaspoon of ground espresso coffee for each cup. If you like your espresso stronger, add more coffee. The lid or upper pot is tightly screwed in place to form a seal and the top container, the pot, is inserted in place. On models we currently sell, the lid for the lower chamber is also the base of the upper pot.