  We present an explicit and simple form of the renormalization group equation
which governs the quantum evolution of the effective theory for the Color Glass
Condensate (CGC). This is a functional Fokker-Planck equation for the
probability density of the color field which describes the CGC in the covariant
gauge. It is equivalent to the Euclidean time evolution equation for a second
quantized current-current Hamiltonian in two spatial dimensions. The quantum
corrections are included in the leading log approximation, but the equation is
fully non-linear with respect to the generally strong background field. In the
weak field limit, it reduces to the BFKL equation, while in the general
non-linear case it generates the evolution equations for Wilson-line operators
previously derived by Balitsky and Kovchegov within perturbative QCD.
