A object of this invention is to provide an electrolytic processing method and apparatus that can suppress a change in the electric conductivity of a fluid due to contaminants, such as processing products produced in electrolytic processing, so that the fluid can maintain good flattening properties. The electrolytic processing apparatus of this invention includes: a processing electrode (42) that can come into contact with a workpiece (W); a feeding electrode (44) for feeding electricity to the workpiece (W); a holder (22) for holding the workpiece (W); a power source (26) for applying a voltage between the processing electrode (42) and the feeding electrode (44); a fluid supply section (50) for supplying a fluid between the workpiece (W) and at least one of the processing electrode (42) and the feeding electrode (44); a sensor (80) for measuring the electric conductivity of the fluid; and a control section (84) for changing the processing conditions based on the electric conductivity measured by the sensor (80).