A heat treatment apparatus includes a heating unit, a chamber, an exhaust unit, a partition unit and a switching unit. The heating unit supports and heats a substrate on which a film of a processing liquid is formed. The chamber surrounds the substrate supported by the heating unit. The exhaust unit is configured to discharge a gas from an inner space of the chamber through a discharge opening located near the heating unit. The partition unit is configured to partition the inner space of the chamber into a first space where the substrate on the heating unit is exposed and a second space located above the first space. The switching unit is configured to switch between a first state where the gas is discharged by the exhaust unit through the first space and a second state where the gas is discharged by the exhaust unit through the second space.