Two‐layer In–Pb films with a thickness from 50 to 200 nm, which are obtained by the method of sequential vacuum condensation, are used to study the phase diagram in this binary system. In–Pb films with a smooth composition change (0–100%) and annealing temperature (20–400 °C) are obtained within a single experimental cycle. The original method of variable composition and variable state is used. With this method of obtaining, the boundaries are observed on the substrate separating different regions of the film. X‐ray diffraction studies show that these areas correspond to different phase states of the sample and visualize the phase diagram of a binary system. The In–Pb phase diagram observed in the films generally corresponds to that for bulk samples. With an increase in the annealing temperature, the dispergation of the films intensifies. Below the liquidus temperature, the films consist of inhomogeneous in composition particles of irregular shape. Above the liquidus line, the films consist of homogeneous islands in the form of a spherical segment. Their size distribution is unimodal with a maximum; the position of which in a wide range does not depend on the concentration of the components.