To provide a window frame of a game machine, which has a member made of an aluminum alloy and a member made of a synthetic resin and not requiring work of connecting both the members with a screw, etc.

Since an aluminum section 15 made of the aluminum alloy and plastic sections such as a window edge plastic section 25, outer edge plastic sections 26, 27, and 28, and a rail holding part 29 are joined by the insert molding in the window frame 2, the molding of the plastic sections and the joining of the aluminum section 15 and the plastic sections are simultaneously performed. Namely, after forming the plastic sections, work of connecting this plastic sections and the aluminum section 15 with the screw, etc. is unnecessary and a manufacturing process becomes simple. Because of the structure that a fine irregularity layer is formed in the surface joined to the plastic section of the aluminum section 15 and that the aluminum section 15 and the plastic section are joined by an anchor effect by some plastic sections' entering the fine irregularity layer, the aluminum section 15 and the plastic sections are firmly joined.