Title: Symmetric algebras, skew category algebras and inverse semigroups; Autor: C.C. Todea; Address: Department of Mathematics, Technical University of Cluj-Napoca, Str. G. Baritiu 25, Cluj-Napoca 400027, Romania; Abstract: We use results from the theory of inverse semigroups to identify and define a class of symmetric algebras, which we call inverse-symmetric algebras. For a finite inverse category $\mathcal{C}$ we define the skew category algebra associated to a $\mathcal{C}$-algebra, which satisfies some additional properties, and we prove that remains inverse-symmetric. The classical examples of symmetric algebras: matrix algebra, Iwahori-Hecke algebra and the (twisted) group algebra are inverse-symmetric. Status: published/2012.