Disclosed is a tension mask frame assembly manufacturing apparatus for mounting a tension mask on a rectangular frame having: a pair of support frame parts to which mutually facing edges of a tension mask having a rectangular sheet shape are fixed; and a pair of connection frame parts for mutually connecting both ends of the support frame parts. The manufacturing apparatus comprises: a frame loading unit for loading the tension mask frame assembly; a pressing unit for pressing the support frame parts along the direction of the plate surfaces of support frames between both ends thereof; and a control unit for controlling the pressing unit so as to pre-deform the support frames in correspondence to at least a part of the bending deformation amount of the support frame parts according to the weight of the support frame parts and the tension of the tension mask.