A window bonding apparatus is provided. The window bonding apparatus includes a resilient display panel supporter supporting a flexible display panel thereon, a holding member supporting and squeezing inwardly opposed ends of the display panel supporter so as to attain a desired degree of curvature, a first jig disposed under the display panel supporter and having a rigid first face with which the bottom face of the display panel supporter comes into contact when pressed from above, and a second jig disposed above the display panel supporter and having a second face to which the window is releaseably attached, the second jig being movable toward the display panel, wherein the second jig is moved to the first jig to attach the window to the display panel in a manner which progressively increases contact area between the window and the display panel.