Abstract <p>In the Simulated Body Fluid (SBF) model solution at pH 7.3, apatite foam spheres were formed on calcium phosphate foam ceramics consisting of β-/α-tricalcium phosphate and β-calcium pyrophosphate. The microporous structure of the calcium phosphate foam ceramics is formed by rounded conglomerates 2–10 μm in size with micropores 2–8 μm in diameter. Application of one layer of hydroxyapatite led to an increase in the size of the conglomerates to 30 μm and a decrease in the micropores to 1 μm. Application of the second layer of hydroxyapatite contributed to smoothing the surface of the foam ceramics, “healing” microcracks and forming a structure with a small amount of micropores. “Apatite foam” was formed on calcium phosphate foam ceramics with one or two layers of crystalline hydroxyapatite in the SBF model solution. The presence of crystalline hydroxyapatite induced the formation of a crystallochemically similar apatite according to the epitaxial principle. After keeping the foam ceramics in the SBF solution, the amount of β-tricalcium phosphate decreased to 60%, β-calcium pyrophosphate to 5%, and the phases of α-tricalcium phosphate to 22% and apatite to 13% were formed. Keeping the foam ceramics reinforced with one or two layers of hydroxyapatite in the SBF solution led to an increase in the content of hydroxyapatite and newly formed apatite to 32–38% with an insignificant change in the content of α-tricalcium phosphate to 48–50% and β-tricalcium phosphate to 14–18%.</p>