Following the thin-layer chromatographic examinations of the acetone extractive of two lichens : Manegazzia asahinae (YAS. ex ZAHLBR.) SANT. and M. terebrata (HOFFM.) Mass, which have been disclosed to contain the same kinds of metabolites, a new depsidone named menegazziaic acid (4) has been isolated from M. terebrata in addition to stictic acid (1), atranorin (2), constictic acid (3), and chloroatranorin (5) The structure of menegazziaic acid has been established as 4, in which the formyl function at C-3 of stictic acid (1) is replaced by a hydroxyl, on the basis of chemical and physicochemical evidence including the chemical conversion of menegazziaic acid to stictic acid (1).