One of the fundamental properties of the Higgs boson, its mass, is measured by way of studying the invariant mass of the $4\ell$ and diphoton decay channels with about 36~fb$^{-1}$ of data collected by the ATLAS experiment. Since in these channels the final state can be fully reconstructed, an invariant mass peak with a good experimental resolution can be obtained in a model independent way and used as an input to compare other Higgs properties measurements with the SM predictions. The measured values of the Higgs boson mass for the $H \to ZZ^* \to 4\ell$ and $H\to\gamma\gamma$ decay modes are $ m_H = 124.88\pm{0.37} \ (\mathrm{stat}) \pm 0.05 \ (\mathrm{syst}) $ GeV and $ m_H = 125.11 \pm{0.21} \ (\mathrm{stat}) \pm{0.36} \ (\mathrm{syst}) $ GeV respectively, and the mass derived from the combined fit is $ m_H = 124.98 \pm{0.19} \ (\mathrm{stat}) \pm{0.21} \ (\mathrm{syst})$ GeV. These results are in good agreement with the LHC Run-1 average of $125.09\pm0.24$ GeV.