The invention relates to a device (1) for heating a fluid (9), comprising a housing (2) having a housing shell (3), a housing base (4) and a housing cover (5), further comprising at least one inlet opening (11) and at least one outlet opening (13) for the fluid (9). At least two electrodes are disposed in the housing (2) at a distance (25) from one another, and each electrode is electrically conductively connected to a pole of at least one pulse generator (20). At least one further electrode (45 or 46) or at least two further electrodes (45, 46), which is or are electrically conductively connected to a power source (47), are disposed in the reaction chamber (12).