The invention provides an etching method of tantalum nitride TaN film, comprising the steps of a, in a first period, introducing first etching gas into a reaction chamber such that TaN and the first etching gas engage in interfacial reaction to generate a first etching product; b, in a second period, introducing second etching gas into the reaction chamber; c, cyclically executing the steps a and b until TaN is completely removed; in the TaN etching method provided herein, it can be guaranteed in the whole etching process that different areas of the TaN film are at uniform etching rate, and therefore after etching of the whole TaN film material, both cases are avoided that a local area experiences over-etching and the layer structure below the TaN film is damaged by over-etching. Therefore, compared with the prior etching method, the etching method provided herein can provide increased compatibility for the etching process and increased yield for products.