Storage device and method of manufacturing switching layer

Embodiments provide a storage device capable of maintaining characteristics of a memory cell and reducing a leak current, and a method of manufacturing a switching layer. A storage device includes a memory cell including a variable resistance element and a switching element having snapback current-voltage characteristics. The switching element includes a first conductive layer in contact with the variable resistance element, a second conductive layer, and a switching layer provided between the first conductive layer and the second conductive layer. The switching layer includes at least one switching member and a first insulating layer having a thermal conductivity higher than 1.4 W/m/K. A cross-sectional area of the switching member at a connection surface between the switching layer and the first conductive layer and a cross-sectional area of the switching member at a connection surface between the switching layer and the second conductive layer are each smaller than a cross-sectional area at a connection su