A new all refractory Josephson junction, in which Yb oxide is used as a tunneling barrier, has been fabricated by the self‐aligned contact process. The heat formation energy of Yb oxide is higher than that of Al oxide. It is expected that a junction with Yb oxide would be more stable than one with Al oxide. The obtained current‐voltage characteristic isVm=15 mV at the critical current densityjJ=1500 A/cm2. Its dielectric constant and barrier height are compared with Al oxide.