The present invention provides an infusion fluid heating apparatus 10 applicable to various types of infusion tubes with different length dimensions. A front-side tube fitting groove 50 or a rear-side tube fitting groove 60 formed on one of surfaces of a heating plate 40 receives an infusion tube TU in a first length between an inlet opening 52 or 62 and an outlet opening 54 or 64 open at the end surfaces of the heating plate 40, and it also receives the infusion tube TU in a second length shorter than the first length. Therefore, the groove uses the second length for a relatively short infusion tube TU, capable of heating the tube appropriately and achieving high versatility. In addition, the tube fitting groove uses the first length for an infusion bag B with a relatively long infusion tube TU, capable of heating the tube appropriately and increasing the maximum infusion fluid flow.