Abstract: Apparatus for measuring the operating parameters of espresso coffee machines, including: a filter-holder body configured to be associated with a water dispensing nozzle of an espresso coffee machine; said body internally defining a chamber for the passage of the water dispensed by said nozzle; a filling element arranged in said chamber and having a cavity for the passage of the water dispensed by the nozzle towards an outlet duct; a water outlet terminal element associated with said filter-holder body downstream of said chamber and defining said water outlet duct; and reading means for the water pressure and temperature values passing from the chamber to the outlet duct; said reading means include at least one pressure reading device operatively engaged with said water outlet terminal element and at least one temperature reading device operatively engaged at said cavity obtained in the filling element.