A display device comprising: a first base having a display area (DA) and a non-display area (NDA); light-emitting elements (ED1, ED2, ED3) on the first base , the light-emitting elements (ED1, ED2, ED3) being located in the display area (DA); a capping layer over the light-emitting elements (ED1, ED2, ED3); and an encapsulation layer over the capping layer and the light-emitting elements (ED1, ED2, ED3), wherein the encapsulation layer comprises: a first inorganic layer ; an organic layer on the first inorganic layer , wherein the first inorganic layer is positioned between the capping layer and the organic layer ; and a second inorganic layer on the organic layer , wherein the first inorganic layer comprises: a first buffer layer (BF1) on the capping layer ; a first barrier layer (BR1) on the first buffer layer (BF1); a first porous layer (PL) on the first barrier layer (BR1); a second barrier layer (BR2) on the first porous layer (PL); and a second buffer layer (BF2) on the second barrier layer (BR2), wherein a refractive index of the first buffer layer (BF1), a refractive index of the first barrier layer (BR1), and a refractive index of the first porous layer (PL) are different from one another, and wherein the refractive index of the first porous layer (PL) is smaller than the refractive index of the first buffer layer (BF1) and the refractive index of the first barrier layer (BR1). a first base having a display area (DA) and a non-display area (NDA); light-emitting elements (ED1, ED2, ED3) on the first base , the light-emitting elements (ED1, ED2, ED3) being located in the display area (DA); a capping layer over the light-emitting elements (ED1, ED2, ED3); and an encapsulation layer over the capping layer and the light-emitting elements (ED1, ED2, ED3), wherein the encapsulation layer comprises: a first inorganic layer ; an organic layer on the first inorganic layer , wherein the first inorganic layer is positioned between the capping layer and the organic layer ; and a second inorganic layer on the organic layer , a first inorganic layer ; an organic layer on the first inorganic layer , wherein the first inorganic layer is positioned between the capping layer and the organic layer ; and a second inorganic layer on the organic layer , wherein the first inorganic layer comprises: a first buffer layer (BF1) on the capping layer ; a first barrier layer (BR1) on the first buffer layer (BF1); a first porous layer (PL) on the first barrier layer (BR1); a second barrier layer (BR2) on the first porous layer (PL); and a second buffer layer (BF2) on the second barrier layer (BR2), a first buffer layer (BF1) on the capping layer ; a first barrier layer (BR1) on the first buffer layer (BF1); a first porous layer (PL) on the first barrier layer (BR1); a second barrier layer (BR2) on the first porous layer (PL); and a second buffer layer (BF2) on the second barrier layer (BR2), wherein a refractive index of the first buffer layer (BF1), a refractive index of the first barrier layer (BR1), and a refractive index of the first porous layer (PL) are different from one another, and wherein the refractive index of the first porous layer (PL) is smaller than the refractive index of the first buffer layer (BF1) and the refractive index of the first barrier layer (BR1). <EOS>