Provided is a technique including forming a film on a substrate, the film including a first element and a second element different from the first element, by performing a cycle a predetermined number of times. The cycle includes: forming a first layer including the first element by supplying a gas containing the first element to the substrate, wherein the first layer is a discontinuous layer, a continuous layer, or a layer in which at least one of the discontinuous layer or the continuous layer is overlapped; and forming a second layer including the first element and the second element by supplying a gas containing the second element to the substrate to modify the first layer under a condition where a modifying reaction of the first layer by the gas containing the second element is not saturated.