An injection molding machine comprises a stationary platen 46 and a movable platen 40. The stationary platen 46 and movable platen 40 may be supported on a base frame 10. A mold clamping frame 56 comprises a first member 54 joined to the stationary platen 46, a second member 24 joined to the movable platen 40, and connecting members 78 and 80 for connecting the first member 54 and the second member 24 at their approximate centers. A mold clamping cylinder 50 is disposed between the first member 54 and the stationary platen 46 or between the second member 24 and the movable platen 40. The stationary platen 46 and the first member 54 are joined in a flexible manner, and the movable platen 40 and the second member 24 are similarly joined in a flexible manner.