A carbon dioxide electrolytic device of an embodiment includes: an electrolysis cell including a cathode, an anode, a gas supply flow path, a solution supply flow path, and a separator; a CO2 gas supply unit configured to supply CO2 gas to the gas supply flow path; an electrolytic solution supply unit configured to supply an electrolytic solution to the solution supply flow path; and a rinse material supply unit configured to supply a rinse material to the gas supply flow path. The gas supply flow path has a first opening, a second opening, and an auxiliary flow path provided to a part of a flow path between the first opening and the second opening, and configured to make at least the rinse material flow therethrough. A switching mechanism configured to switch a flow direction of the rinse material in the auxiliary flow path is connected to the gas supply flow path.