I discuss the neutrinoless double beta decay in the nuMSM which is the extended standard model by introducing three right-handed neutrinos with the masses below the electroweak scale. The tiny neutrino masses, the baryon asymmetry of the universe, and the dark matter can be explained simultaneously in the model. In this model, I will show a possibility of the enhancement of the effective mass of neutrinoless double beta decay in the inverted hierarchy of the active neutrino masses when the right-handed neutrinos are less than 1GeV. This talk is based on our recent paper, 1606.06686.