The multi-chamber heat treatment device includes intermediate conveyors connected together, each treatment conveyor of the intermediate conveyors is attached with a treater that applies predetermined heat treatment to a treatment object and conveys the treatment object to the treater, and each treater is either one of a main treater that applies main treatment to the treatment object, a preheater that applies preheating treatment to the treatment object before the main treatment, and a cooler that applies cooling treatment to the treatment object after the main treatment.