A carbon dioxide treatment apparatus, a carbon dioxide treatment method, and a method for producing a carbon compound that have high energy efficiency in recovery and reduction of carbon dioxide and are highly effective in reducing loss of carbon dioxide. The carbon dioxide treatment apparatus (100) includes a recovery device (1) configured to recover carbon dioxide, an electrochemical reaction device (2) configured to electrochemically reduce carbon dioxide, and a pH adjuster (52), wherein pH of a cathode side electrolytic solution is higher than that of an anode side electrolytic solution, carbon dioxide gas is supplied from a concentration part 11 to a gas flow path on a side of a cathode (21) opposite to an anode (22), and the carbon dioxide gas is reduced at the cathode (21).