For the first time tunnel junctions are prepared by a selective niobium etching process from Nb‐Al‐AlOx‐Al‐Nb sandwiches electron beam evaporated in ultrahigh vacuum. A quality factor ofVm=27 mV at 4.2 K has been obtained by cooling the Nb base electrode before Al deposition. The cooling of the Nb base layer had a considerable influence on the subgap current below 4.2 K. The temperature dependence of the subgap current down to 1.5 K is compared to the BCS prediction.