To provide a treatment device capable of effectively heating an object of heating whose temperature should be lowered after the heating by heating a fluid to be sterilized by a heat pump device and further cooling the fluid.

A heat-pump type sterilization device 1 is structured to heat and sterilize the object of sterilization flowing in a channel 1A by a heat pump 1B with a refrigerating cycle consisting of a compressor 11, a heat exchanger 31 for heating, an expansion valve 13 as a depression device, and a heat exchanger 33 for cooling, etc. The object of sterilization is heated/sterilized and cooled in the channel 1A, and after that, the object of sterilization is fed to a medium of using the object.