Our electroweak vacuum may be metastable in light of the current experimental data of the Higgs/top quark mass. From the viewpoint of cosmology, an interesting consequence is that high-scale inflation has a tension with the metastability.In order to overcome this problem, Higgs-inflaton/-curvature couplings are often introduced to stabilize Higgs during inflation. However, after inflation, the mass term induced by the additional coupling oscillates during the preheating era, and it can potentially destabilize the electroweak vacuum via resonant production of Higgs. In this talk, we study whether the Higgs-inflaton/-curvature coupling can save the electroweak vacuum by taking account of Higgs production during the preheating stage. In particular, we put upper bounds on the Higgs-inflaton/-curvature coupling.