An apparatus for brewing coffee includes: a filter cup movably supported on a supporting member of a main frame and configured with a receiving space a control rod connected pivotally to an axle rod disposed above the supporting member and a piston rod connected pivotally to the control rod and connected fixedly to a piston that is disposed fittingly and movably in the filter cup to divide the receiving space into upper and lower space parts. The piston is operable, based on rotation of the control rod, in a communicating state when moving upwardly and in a closed state when moving downwardly. When the control rod rotates to move downwardly the piston, ground coffee contained in the lower space part is pressed by the piston to the bottom of the lower space part. A method of brewing coffee performed by the apparatus is also disclosed.