A brewing device (1) for a coffee machine comprises a brewing cylinder (2) with a cylindrical bore (3), an upper piston (5) and a lower piston (4), by means of which the brewing cylinder (2) is able to be closed off to form a brewing chamber (6). The surface of the upper piston (5) and of the lower piston (4) facing the brewing chamber (6) is provided in each case with a sieve (11, 12), through which hot water is able to be conducted into the brewing chamber (6) or coffee is able to be discharged from the brewing chamber (6) in each case via a connecting channel (7, 8) provided in the respective piston (4, 5). At least one of the sieves (11, 12) is installed on a supporting structure (9, 10) that is placeable on one of the pistons (4, 5) and is lockable therewith. The respective supporting structure (9, 10) is provided with a connecting element (13, 14), which is connectable in a sealed way to the connecting channel (7, 8) of the respective piston (4, 5). By means of this arrangement the sieve can be easily taken out of the respective piston and put back in again.