To provide a heating furnace capable of maintaining a sound combustion state of a secondary combustion type burner of a preheating zone, and capable of reducing running costs and improving heat treatment quality of a heating object.

The heating furnace 1 is provided with the preheating zone X, a heating zone Y, and a soaking zone Z sequentially from a charging side A toward an extraction side B. The first burner 2 of a secondary combustion type is arranged in the preheating zone, and a second burner 3 other than a secondary combustion type is arranged in at least the heating zone. An opening 5 communicated with a flue 4 is provided between the preheating zone and the heating zone. The first burner is a heat storage type burner alternately repeating combustion and heat storage.