Abstract: Apparatus for separating oil and water comprising a pipe coiled annularly along the inner surface of the upper portion of a treating chamber and containing therein a large number of small diameter members arranged parallel to one another. The pipe is connected at its lower end to an inlet for an oil and water liquid mixture and the pipe is open at its upper end to form a rough separating section having an upper oil accumulating portion with an oil discharge pipe. A distribution layer is mounted below the rough separating section to form a flow distribution section for passage of a roughly separated water therethrough. A filter tube having a wall composed of a filter layer comprising a mixture of lipophilic fibers and hydrophilic fibers is mounted in a lower portion of the treating chamber to form a fine separating section having an oil accumulating portion at the top thereof with an oil discharge pipe and a separated water discharge pipe at the bottom thereof.