To solve a problem of a long time required for a temperature drop after heat treatment of a work and a temperature rise at work replacing time in a conventional heating furnace device.

This heating furnace device has a heating element installed on a furnace wall. A reactor vessel can be freely inserted into and extract from a heating space surrounded by this heating element. A cooling jacket is freely inserted and extracted between the heating space and the heating element. A work holder is freely inserted into and extracted from the reactor vessel.