In a coffee maker (1) having a boiler (6) and heating means (62) for heating a content of the boiler (6), safety measures are taken to prevent breakdown of the coffee maker (1) in the case in which the heating means (62) are activated while the boiler (6) is empty. The coffee maker (1) comprises a controller (10) having a memory (15) in which a flag indicating a filled state of the boiler (6) can be raised, which controller (10) is programmed to activate the heating means (62) to supply reduced heating power if the memory (15) does not contain the flag. A situation in which the boiler (6) gets overheated, even if the heating means (62) are shut off after having been operated, is prevented thereby.