Inside a single apparatus main body (100), a surface treatment apparatus includes: a treatment cell (11); a vertical rotation shaft (12); an attachment/detachment device; a receiving tank (15); a cover body (16); a plurality of tanks (21); a plurality of surface treatment liquid supply devices (22); a cleaning water supply device; a drain device (3); and a first cleaning device. Upon operation of the surface treatment liquid supply device while the treatment cell (11) containing small objects is rotated by the vertical rotation shaft (12), a surface treatment is carried out on the small objects, upon operation of the cleaning water supply device, the small objects inside the treatment cell (11) are cleaned, and upon operation of the first cleaning device, the inner face of the cover body and the outer face of the treatment cell are cleaned, thus providing circulation use of surface treatment liquids in the tanks.