The nature of the magnetic ground state of the spin-frustrated molecular magnet {Mo72Fe30} is studied using polarized neutron scattering and specific heat methods. The magnetic scattering cross section up to 2.30 Å−1 has been determined by means of diffuse neutron scattering with xyz polarization analysis at temperatures from 1.5 to 100 K. The spin correlations observed at 1.5 K agree well with the simulation based on the three-sublattice spin configuration model for {Mo72Fe30}. The specific heat of {Mo72Fe30} has been measured from 60 mK to 15 K under zero external magnetic field. The energy gaps, 0.09(1) and 0.64(1) meV, identified by the Schottky-type anomalies in the specific heat data are in reasonable agreement with the low-lying magnetic excitations predicted by the quantum rotational band model for the three-sublattice spin configuration model. Therefore, our experimental study provides strong support that the three-sublattice spin configuration model is a good approach to the magnetic ground state of {Mo72Fe30}.