Аннотация:Recent MMS observations have discovered electron‐scale super‐thin current sheets (STCSs) witha partial electron demagnetization, which distinguishes them from the ion‐scale TCSs traditionally observed bythe Cluster mission. Our investigation focuses on the dynamics of STCSs and reveals new aspects influencingtheir stability. We use the earlier proposed 1D collisionless self‐consistent equilibrium STCS model and showthat the free parameters of this model,such as the relative part of demagnetized electrons, their flow velocity andthe pressure anisotropy of magnetized electron population, can contribute to the development of tearinginstability. With the growth of these parameters, the STCS becomes thinner, which leads to the accumulationexcess of a free energy. Stabilizing energy decreases due to the increase of a relative part of demagnetizedelectrons. Thus, demagnetized electrons in STCSs can provide the development of fast and short‐wavelengthelectron tearing modes.