In this paper, based on scattering theory, we study tunneling conductance in a nano layer which is located between an s-wave superconductor and a ferromagnetic metal. The model is a double junction system as FM/NM/SC, in which FM is a ferromagnetic metal with exchange field of h, SC is a spin singlet s-wave superconductor and NM is a normal metal, with a barrier potential V. The thickness of intermediate layer varies between 1 nm to 1000 nm. We have found that the conductance oscillates as a function of bias voltage in a way that the period of oscillations does not depend on h, but depends on potential V. We have found the relation of the oscillations period in terms of V by two approaches: Analytic approach and numerical approach and we have observed that there is good agreement between these two approaches.
