Providing a heat treatment apparatus capable of realizing a more compact configuration.
Heat treatment apparatus 1 has to form a refrigerant passage 48 for supplying the refrigerant to the object to be processed 100, the coolant passage forming body 42. Coolant passage formation member 42 includes an upper member 50 and lower member 49 as a plurality of refrigerant passages forming member, displaced so as to approach each other along the vertical direction Z1 in which these members 49, 50 intersecting the transport direction by being configured to form a refrigerant passage 48 in a state of accommodating the object to be processed 100. Also, the members 49 and 50 vertically in the direction Z1 by displaced to be separated from each other and are configured to permit loading and unloading of the workpiece 100 along the transport direction A1 with respect to the refrigerant passage 48.