Apparatus for and method of etching

A film thickness measuring mechanism is provided in an orienter chamber (A or B) or a transport buffer chamber (5) of an etching apparatus. A wafer subjected to a predetermined etching process in an etching chamber (1), for example, is transported temporarily into the orienter chamber (A or B) or the transport buffer chamber (5) in which the film thickness measuring mechanism, in turn, measures an etch depth for the wafer. If the etch depth is out of predetermined tolerance with respect to an etch depth setting, an additional etching process is performed on the wafer. Etch time for the additional etching process is calculated from the actual etch depth measured by the film thickness measuring mechanism, the etch depth setting, and an etch rate of a film to be etched.