Provided is a heating device for blocking flow of air if the inside of a cartridge enters a negative-pressure state upon discontinuing or completing supply of a transfusion infusion solution or blood being infused into a human body, the device including: a cartridge upper plate which is formed so as to have an inflow port and to have a fluid-guide member for guiding the flow of a fluid a cartridge lower plate which is formed so as to have an outflow port so as to have another fluid-guide member positioned spaced apart from said fluid-guide member a heater which is disposed between the cartridge upper plate and the lower plate and that heats the fluid being guided by means of the fluid-guide members air filters which are positioned outside the fluid-guide members and that are adapted to discharge air bubbles that are generated in the heated fluid into the atmosphere and means which are provided on the cartridge upper and lower plate fluid flow pathways, that keep the flow of fluid normal in the positive-pressure state and block the fluid movement pathway if a negative pressure occurs inside the cartridge.
