An etching method includes preparing a substrate in which titanium nitride and molybdenum or tungsten are present, and etching the titanium nitride by supplying a processing gas including a ClF3 gas and a N2 gas to the substrate, wherein in the etching the titanium nitride, a partial pressure ratio of the ClF3 gas to the N2 gas in the processing gas is set to a value at which grain boundaries of the molybdenum or the tungsten are nitrided to such an extent that generation of a pitting is suppressed.