There is provided a technique that includes: forming a film on a substrate including a recess formed on a surface of the substrate by performing a cycle a predetermined number of times, the cycle including: (a) supplying a precursor gas to the substrate; and (b) supplying a reaction gas to the substrate, wherein in (a), the precursor gas is supplied to the substrate separately a plurality of times, and a processing condition under which the precursor gas is supplied for a first time is set to a processing condition under which self-decomposition of the precursor gas is capable of being more suppressed than a processing condition under which the precursor gas is supplied for at least one subsequent time after the first time.

A substrate processing apparatus includes: a first boat configured to hold substrates in a shelf shape; a second boat provided coaxially with the first boat and configured to hold substrates in a shelf shape; and a drive configured to rotate the first boat and the second boat in a synchronized manner and configured to raise and lower the second boat relative to the first boat.

An embodiment relates to a substrate processing apparatus configured to discharge liquefied fluid. The apparatus may include a reaction tube unit that has an open lower end and defines a reaction space in which a plurality of substrates are processed, a boat unit that is disposed within the reaction tube unit and supports the plurality of substrates in a vertically stacked arrangement, and a boat support unit that supports and vertically moves the boat unit so as to position the boat unit within the reaction space. At least a portion of one surface of the boat support unit may be inclined to allow liquefied fluid in the reaction space to flow downward and be discharged.

There is provided a technique that includes: forming a film on a substrate including a recess formed on a surface of the substrate by performing a cycle a predetermined number of times, the cycle including: (a) supplying a precursor gas to the substrate; and (b) supplying a reaction gas to the substrate, wherein in (a), the precursor gas is supplied to the substrate separately a plurality of times, and a processing condition under which the precursor gas is supplied for a first time is set to a processing condition under which self-decomposition of the precursor gas is capable of being more suppressed than a processing condition under which the precursor gas is supplied for at least one subsequent time after the first time.