Dynamical symmetry breaking in three dimensional QED with $N$ flavors, which has been mostly analyzed by solving the Schwinger-Dyson equations, is investigated by means of the approximated Wilson, or non-perturbative, renormalization group (RG). We study the RG flows of the gauge coupling and the general four-fermi couplings allowed by the symmetry with concentrating our interest on study of the phase structure. The RG equations have no gauge parameter dependence in our approximation scheme. It is found that there exist chirally broken and unbroken phases for $N > N_{rm cr}$ ($3 < N_{rm cr} < 4$) and that the unbroken phase disappears for $N < N_{rm cr}$. We also discuss the spontaneous parity breaking in three dimensional QED with the four-fermi interactions.
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