In this paper, we have analyzed the contribution of the magnetic stress energy to thernsupernova bounce. A calculation of Maxwell stress tensor is proposed when leads to thernexpression of the magnetic force density. By making the link between the the magneticrnforce density and the Maxwell stress tensor we derived the magnetic pressure, requiredrnto ensure core stability or support the star from gravitational collapse, we calculated thernassociated eld stranght at the surface of the compact object (the neutron star- NS) tornbe B & 1018 G and showed that this eld is exert a pressure Pmag 1035 grncms2 which isrnable to cause supernova bounce of the infalling stellar material