According to one embodiment, an electrolytic device includes an electrolytic cell including a first electrode, a second electrode opposing the first electrode and a diaphragm provided between the first electrode and the second electrode. The first electrode is formed of a plate including a first surface opposing the diaphragm, a second surface located on an opposite side to the diaphragm, and first recess portions formed in the first surface with a first pattern. The first recess portions include a bottom surface apart from the first surface and through-holes opening to the second surface of the first electrode and to a part of the bottom surface.