Heat treatment furnace

A heat treatment furnace comprising:

• a furnace body comprising an entrance, an exit, and a heat treatment space having a temperature-rising space and a temperature-maintained space that are configured to thermally treat a plurality of objects;
• conveying plates on which the plurality of objects is to be placed in a state of being stacked on one another in an up-down direction;
• a pusher configured to push the conveying plates in a front direction from the entrance to the exit of the furnace body;
• and
• a plurality of heaters extending in the up-down direction and aligned in the front direction in the heat treatment space,
• wherein
• each of the plurality of heaters comprises a heating part configured to generate heat, and
• positions of the heating parts of the plurality of heaters in the up-down direction vary from the heater closest to the entrance toward the heater closest to the exit.