In the presence of an imide compound (e.g., N-hydroxyphthalimide) shown by the formula (2): ##STR00001## wherein R.sup.1 and R.sup.2 independently represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cycloalkyl group; or R.sup.1 and R.sup.2 may bond together to form a double bond or an aromatic or non-aromatic ring; Y is O or OH and n=1 to 3; or the imide compound and a co-catalyst (e.g., a transition metal compound), an adamantane derivative having a functional group such as a nitro group, an amino group, a hydroxyl group, a carboxyl group, a hydroxymethyl group and an isocyanato group is oxidized with oxygen. According to the above method, an adamantane derivative having a hydroxyl group together with a functional group such as a nitro group, an amino group, a hydroxyl group, a carboxyl group, a hydroxymethyl group and an isocyanato group is efficiently obtained.