In this work, thin Mn₄Si₇ films are grown by the solid-state ion-plasma method using a magnetron-sputtering device, and their surface morphology, crystal structure, Miller indices, lattice parameters, thermoelectric and electro-physical parameters of the films are measured. Seebeck coefficient decreases, and finally, the sample is changed from p-type to n-type. Power factor turns out to be small (P ≅ 1–4 mW/(m⋅K²)) and increases very little in the temperature range of 300–450 K and increases sharply in the range of 500–580 K (P ≅ 850–3690 mW/(m⋅K²)). As the thickness decreases, the power factor increases. The band gap at room temperature for the sample prepared by the ion-plasma method is measured optically to be Eg = 0.354 eV. Studies show that Mn₄Si₇ layers with a size of ≤ 40 nm can be grown on the surface of the Si crystal formed by the magnetron sputtering, but the Si crystal does not form a full-size Mn₄Si₇ layer. During thermal heating at 300–750 K, nanosize bubbles are observed to form in the thin Mn₄Si₇ coating grown under vacuum conditions; then, they are ruptured and the nanosize defects are formed. Then, at 750 K, the defects narrow down to form a single thin Mn₄Si₇ coating. The measurement results show that the thin films grown by the solid-state ion-plasma method are formed and their thermoelectric and electrophysical properties are improved.