‎The main purpose of this paper is to introduce and investigate a new class of open sets called $\delta_e$-open sets‎. For this aim‎, ‎first we define and study the notion of $e$-regular open set via $e$-closure operator‎. ‎Then‎, ‎we introduce the notion of $\delta_e$-open set via $e$-regular open set‎. ‎Several fundamental properties of the notion of $\delta_e$-open set have been revealed‎. ‎Also‎, ‎we show that the family of $\delta_e$-open sets is a topology strictly weaker than $\tau^{\delta}$ and stronger than $\tau$‎. ‎In addition‎, ‎we investigate relationships between the notion of $\delta_e$-open set and other existing notions in topology such as open sets‎, ‎regular open sets and $\delta$-open sets‎. ‎Furthermore‎, ‎we give not only various properties and characterizations but also examples and counterexamples‎. ‎Finally‎, ‎some properties related to separation axioms are revealed‎. پرونده مقاله