Espresso coffee machine comprising a reservoir for the water (20), a pump (21) for delivering the said water to a boiler (24), a hot water supply unit (2, 102, 122, 4, 304), and filter holder means (1, 301, 3, 103) for housing a portion of ground coffee (16), preferably pre-packaged, and provided with coffee delivery means (201; 203), characterized in that the said supply unit (2, 102, 122, 4, 304) and the said filter holder means (1, 301; 3, 103) are coupled together with a seal and the trajectory of the coupling movement lies on a plane substantially perpendicular to the median plane of coupling of the said supply unit (2, 102, 122; 4, 304) and the said filter holder means (1, 301; 3, 103), the facing surfaces of the said supply unit (2, 102, 122; 4, 304) and the said filter holder means (1, 301; 3, 103) coming into contact only at the time of their coupling.