Geothermal study of the territory of Ukraine is unique. A network of Earth's heat flow (EF) determinations in 13000 boreholes has been created here. All TP values were corrected for the influence of paleoclimate, non-horizontal groundwater overflows, geologic structures, thrusts, and young sedimentation. Maps of the depth (corrected) TP were constructed. In terms of network density it has no analogues among the maps for comparable areas. An interpretation system was developed, which allows building thermal models of the crust and upper mantle taking into account stationary and non-stationary heat sources, and their independent control was carried out. The density distribution of geoenergetic resources of Ukraine was studied. Their total amount exceeds the reserves of all combustible minerals by 25 times.