In this paper, we prove that the full automorphism group of the derangement graph Gamma(n) (n >= 3) is equal to (R(S-n) x Inn(S-n)) x Z(2), where R(S-n) and Inn(S-n) are the right regular representation and the inner automorphism group of S-n respectively, and Z(2) = <phi > with the mapping phi : sigma(phi) = sigma(-1), (sic)sigma is an element of S-n. Moreover, all orbits on the edge set of Gamma(n) (n >= 3) are determined.