In one embodiment of an apparatus for manufacturing a rubber sheet, a continuous rubber material is supplied onto a supply conveyor in a meandering state by supplying the continuous rubber material onto the supply conveyor while moving rubber supply device in a reciprocating manner in a roll axial direction. The rubber supply device has a full width moving mode in which the rubber supply device moves in the roll axial direction such that the continuous rubber material has a meandering shape of a width corresponding to a width of a rubber sheet, and a partial width moving mode in which the rubber supply device moves in the roll axial direction such that the continuous rubber material has a meandering shape of a width obtained by excluding widths of both edge portions of the rubber sheet from the width of the rubber sheet.