An optically active manganese complex of the formula I or I': ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently represent hydrogen atom, C.sub.1 -C.sub.4 alkyl group, phenyl group which may be substituted by a halogen atom, C.sub.1 -C.sub.4 alkyl group, C.sub.1 -C.sub.4 alkoxyl group, cyano group or nitro group; and any two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 together form the C.sub.4 -C.sub.8 ring, X.sup.- represents a counter anion which may form a salt, Y represents hydrogen atom, halogen atom, C.sub.1 -C.sub.4 alkyl group, C.sub.1 -C.sub.4 alkoxyl group, nitro group or cyano group, R represents hydrogen atom, C.sub.1 -C.sub.4 alkyl group, phenyl group which may be substituted by halogen atom, C.sub.1 -C.sub.4 alkyl group or C.sub.1 -C.sub.4 alkoxyl group, or substituted silyl group and a process for producing epoxy compounds using the complex as a catalyst.