Abstract: An improved structure of brewing chamber of a coffee machine is disclosed by setting an intercepting device in an extracting pipe of a traditional brewing chamber of a coffee machine and two draining through-holes into the bottom of the traditional brewing chamber. Due to the intercepting device, the extracted coffee liquid coming from the brewing chamber can be drained off the extracting pipe with a stable speed and the coffee grain in the brewing chamber can be extracted in the conditions with an average extracting time and an average extracting pressure, and all that promote the extracting and tasting quality of the coffee. Besides, by the two draining through-holes, after all the extracted coffee liquid has been drained off the extracting pipe, the residual liquid in the brewing chamber can be drained off the brewing chamber smoothly to keep the next time extracted coffee liquid fresh.