Process for obtaining health- and environmentally acceptable, chemically neutral and inert construction material, wherein the concentration of water soluble compounds of heavy metals in such material does not exceed pre-determined limit values, namely As ≤ 0,50 mg / kg of dry matter in such obtained construction material; Cd ≤ 0,04 mg / kg of dry matter in such obtained construction material; Pd ≤ 0,50 mg / kg of dry matter in such obtained construction material; Zn ≤ 4,00 mg / kg of dry matter in such obtained construction material; and wherein said material is obtained from a contaminated soil containing water soluble chemical compounds of heavy metals, which are harmful for the environment and human health, wherein the concentration thereof essentially exceeds the previously mentioned limit values, namely As = 1,00 − 10,00 mg / kg of dry matter in said contaminated soil; Cd = 0,10 − 1,00 mg / kg of dry matter in said contaminated soil; Pb = 1,00 − 10,00 mg / kg of dry matter in said contaminated soil; and Zn = 5,00 − 50,00 mg / kg of dry matter in said contaminated soil; wherein the process comprises the following steps: i) preparation of the contaminated soil, which includes excavation and separation of dry particles of contaminated soil by means of sieving in order to obtain fractions below 32 mm and above 32 mm, upon which the fraction of particles above 32 mm is crushed to granulation below 32 mm and temporarily deposited; ii) mixing of such obtained and prepared contaminated soil according to step i) with a dispersion of Fe-nanoparticles; iii) adding dry bentonite clay in powder form to said mixture of prepared contaminated soil and Fe-nanoparticles by taking into consideration content of the clay fraction within the contaminated soil itself, which is then followed by homogenization of such obtained mixture; iv) adding calcareous fly ash, which is followed by mixing and optionally adjusting moisture to optimum value with deviation of ± 2 %.; v) application of such obtained material by spreading to layers having thickness up to 30 cm and compacting such established layer of construction material by means of suitable building machinery, so that the average density of such compacted layer is ≥ 95 % of the density of the mixture, which is obtained by means of modified Proctor method. i) preparation of the contaminated soil, which includes excavation and separation of dry particles of contaminated soil by means of sieving in order to obtain fractions below 32 mm and above 32 mm, upon which the fraction of particles above 32 mm is crushed to granulation below 32 mm and temporarily deposited; ii) mixing of such obtained and prepared contaminated soil according to step i) with a dispersion of Fe-nanoparticles; iii) adding dry bentonite clay in powder form to said mixture of prepared contaminated soil and Fe-nanoparticles by taking into consideration content of the clay fraction within the contaminated soil itself, which is then followed by homogenization of such obtained mixture; iv) adding calcareous fly ash, which is followed by mixing and optionally adjusting moisture to optimum value with deviation of ± 2 %.; v) application of such obtained material by spreading to layers having thickness up to 30 cm and compacting such established layer of construction material by means of suitable building machinery, so that the average density of such compacted layer is ≥ 95 % of the density of the mixture, which is obtained by means of modified Proctor method.