Abstract: A flotator for use in benefication, coal dressing, wet refining and so forth, incorporating a surface flotation technic. The flotator has a funnel-shaped liquid cell having a bottom of an area smaller than that of the top opening. A bubbling device is constituted by an upper sleeve partly immersed in the liquid contained by the cell, a lower sleeve disposed coaxially with the upper sleeve and fully immersed in the liquid. The upper end of the lower sleeve is spaced by a predetermined distance from the lower end of the upper sleeve to form therebetween a spaced region located at a small depth from the liquid surface. The bubbling device further has a rotary blade unit constituted by upper and lower blades separated by a flat partition plate.