Abstract: Rotating biological contactor-type sewage treatment equipment of the present invention comprises a treatment tank 4 for storing sewage to be treated, a rotation shaft 3 which extends across opposed side walls 4a, 4b of the treatment tank 4, a plurality of rotating discs 1 mounted at a predetermined interval on the rotation shaft 3 in such a manner that each disc is partly submerged in the sewage stored in the treatment tank 4, and a driving means for supplying a driving force to the rotation shaft 3 in order to rotate the rotating discs 1. This equipment treats sewage by rotating the rotating discs 1 on which aerobic bacteria are attached, thereby allowing the aerobic bacteria to contact the sewage and aerobically decompose pollutants in the sewage. Each of the rotating discs 1 is composed of n portions of sector-shaped segments 11, wherein n is an integer not less than 1, and each of the sector-shaped segments 11 is composed of two equally divided sector-shaped pieces 11a, 11b.