An apparatus and method for producing a rotor blade spar cap for a rotor blade of a wind turbine. The apparatus includes a mold, which has a cavity-like depression in cross section, in which material for a rotor blade spar cap can be placed, and a sheet-like mold covering for sealing off the depression. The depression has side walls, an opening bounded by the side walls and a base area between the side walls. In accordance with the method, fiber material and/or fiber-reinforced material is placed in the depression of the mold such that the material finishes flush with the side walls with respect to the height of the rotor blade spar cap, the depression is sealed off by the sheet-like mold covering, the material is fused together to form the rotor blade spar cap and the rotor blade spar cap is removed from the mold.