Goncharov, A.2016-02-082016-02-0819970039-3223http://hdl.handle.net/11693/25528We prove that generalized Cantor sets of class α, α ≠ 2, have the extension property iff α < 2. Thus belonging of a compact set K to some finite class α cannot be a characterization for the existence of an extension operator. The result has some interconnection with potential theory.EnglishArticle1730-6337