An object is to provide an ozone production device capable of producing ozone in an electrolysis target liquid easily without performing any laborious assembly operation and with a high efficiency. In the ozone production device, a voltage is applied between an anode and a cathode, and ozone is produced in the electrolysis target liquid by electrolysis, the anode is integrated with the cathode via a predetermined interval without separating the anode from the cathode, and an electrolytic portion is constituted. Moreover, the anode and cathode comprise water-permeability members (mesh form) capable of passing the electrolysis target liquid.