The present contribution is concerned with the modeling of lengthscale-dependent behavior of submicron sized amorphous metal. As these samples reach the size of a few hundred nanometers, the main deformation mechanism changes from catastrophic to a stable shear localization. For the underlying model description, we resort to a thermodynamically consistent approach. Klusemann & Bargmann [1] presented results for a small strain formulation which was extended recently to finite strains by Bargmann et al. [2]. The non-local material model is formulated with a dual mixed finite element approach. It is shown that the proposed finite deformation model is well suited to predict the stable shear localization process in submicron-sized metallic glasses and its size effect. The model confirms the experimental observation that with decreasing sample size the shear localization process becomes stable and delayed. The finite deformation model is able to predict the failure process in submicron-sized metallic glasses as well as the delay of it with decreasing sample size.