A preheating device for the preheating of fuel of an internal combustion engine, - with an inlet connection for connecting the preheating device to a distributor rail of a fuel injection system of the internal combustion engine, - with an outlet connection for connecting a fuel injector of the fuel injection system to the preheating device, - with a preheating chamber, able to be flowed through by the fuel, which is fluidically connected with the inlet connection and with the outlet connection, - with at least one electrical heating element for heating the fuel in the preheating chamber, - with at least one metallic heating body, which is exposed to the fuel in the preheating chamber, characterized in that - the at least one heating element is inserted into said at least one heating body, - the respective heating body has a base section and a dipping section originating from the base section, - the dipping section contains the respective heating element and dips into the preheating chamber so that it comes in contact with the fuel on its outer side, - the base section closes the preheating chamber tightly inside a housing of the preheating device, and has electro-connections (14, 15) for supplying the at least one heating element with electrical energy, - the dipping section has on its outer side - either a flow duct which directs a fuel path, leading from the inlet connection to the outlet connection, in the peripheral direction at least partially around the dipping section, or - several ribs which extend transversely to an axial direction aligned to the outlet connection, and are spaced apart from one another in the axial direction, so that a fuel path leading from the inlet connection to the outlet connection leads through between adjacent ribs. - with an inlet connection for connecting the preheating device to a distributor rail of a fuel injection system of the internal combustion engine, - with an outlet connection for connecting a fuel injector of the fuel injection system to the preheating device, - with a preheating chamber, able to be flowed through by the fuel, which is fluidically connected with the inlet connection and with the outlet connection, - with at least one electrical heating element for heating the fuel in the preheating chamber, - with at least one metallic heating body, which is exposed to the fuel in the preheating chamber, characterized in that - the at least one heating element is inserted into said at least one heating body, - the respective heating body has a base section and a dipping section originating from the base section, - the dipping section contains the respective heating element and dips into the preheating chamber so that it comes in contact with the fuel on its outer side, - the base section closes the preheating chamber tightly inside a housing of the preheating device, and has electro-connections (14, 15) for supplying the at least one heating element with electrical energy, - the dipping section has on its outer side - either a flow duct which directs a fuel path, leading from the inlet connection to the outlet connection, in the peripheral direction at least partially around the dipping section, or - several ribs which extend transversely to an axial direction aligned to the outlet connection, and are spaced apart from one another in the axial direction, so that a fuel path leading from the inlet connection to the outlet connection leads through between adjacent ribs. - either a flow duct which directs a fuel path, leading from the inlet connection to the outlet connection, in the peripheral direction at least partially around the dipping section, or - several ribs which extend transversely to an axial direction aligned to the outlet connection, and are spaced apart from one another in the axial direction, so that a fuel path leading from the inlet connection to the outlet connection leads through between adjacent ribs.