Let X be a smooth scheme with an action of an algebraic group G. We establish an equivalence of two categories related to the corresponding moment map µ: T^∗X → g^∗ - the derived category of G-equivariant coherent sheaves on the derived fiber µ^{− 1}(0) and the derived category of G-equivariant matrix factorizations on T^∗X ×g with potential given by µ.