Storage device using wafer-to-wafer bonding and method of manufacturing the same

A storage device includes a non-volatile memory device. The non-volatile memory device includes a first substrate including a first peripheral circuit region including a row decoder selecting one word line from among a plurality of word lines of a three-dimensional (3D) memory cell array and a second substrate including a second peripheral circuit region, including a page buffer unit selecting at least one bit line from among a plurality of bit lines of the 3D memory cell array, and a cell region including the 3D memory cell array formed in the second peripheral circuit region. The 3D memory cell array is disposed between the first peripheral circuit region and the second peripheral circuit region by vertically stacking and bonding the second substrate on and to the first substrate.