Disclosed is a process for producing an azo compound, which comprises the step of coupling a diazo component comprising an aromatic amine diazonium salt with a coupler component comprising naphtol and/or acetoacetanilide, wherein the coupling is conducted in a agitation apparatus having a main agitation impeller and an auxiliary agitation impeller attached to a rotation axis in an agitation vessel. If required, aging and laking may also be conduced in the agitation apparatus.