Patent ID: 8253075

Claim:
A heat treatment apparatus comprising: a process chamber configured to accommodate objects to be placed in multiple stages and to be treated and performing a predetermined heat treatment; a tubular heater configured to heat the objects to be treated, the heater surrounding an outer circumference of the process chamber; a heat exhaust system configured to exhaust an atmosphere present in a space existing between the heater and the process chamber; and cooling means configured to blow a cooling fluid into the space to cool the atmosphere in the space, wherein the heater includes a tubular heat insulator, a heat generating resistor, and an outer shell, the heat generating resistor being provided on an inner circumference of the tubular heat insulator, the outer shell covering an outer circumference of the tubular heat insulator, the cooling means includes an outlet and an annular flow path in which the cooling fluid flows, the annular flow path being provided between the tubular heat insulator and the outer shell, the outlet being provided in the tubular heat insulator, the cooling fluid in the annular flow path being blown out of the outlet into the inside of the tubular heat insulator, a plurality of annular flow paths are provided between the tubular heat insulator and the outer shell and are arranged in a vertical direction, and a common supply duct is provided on the outer side of the outer shell and extends in the vertical direction, the common supply duct being adapted to supply a cooling fluid to each of the annular flow paths.