A process produces an aromatic compound by bringing an aromatic compound (B) into contact with molecular oxygen (C) in the presence of a catalyst (A) comprising at least one of (A1) a heteropolyacid and/or a salt thereof, and (A2) a mixture of oxoacids and/or salts thereof containing, as a whole, one of P and Si and at least one selected from V, Mo and W to thereby yield another aromatic compound (G) than the aromatic compound (B). The process can produce, for example, a corresponding aromatic hydroxy compound (G1) by allowing the aromatic compound (B) to react with the molecular oxygen (C) further in the presence of a reducing agent (D).