A toggle type mold clamping mechanism for preventing the degradation of parallelism between stationary and movable platens, which is caused due to a clearance between a pin and a bushing, with use of a simple construction. A mold clamping force acting on the pin is transmitted through the bushing to a link L1, thereby moving the movable platen to perform mold clamping. A pre-pressure exerting in the same direction as the direction of a mold clamping force generated at the time of mold clamping is applied by a spring or the like to move the pin toward the link L1. Even a mold opening force is exerted at the time of mold opening, the pre-pressure c provided by the spring or the like keeps the position of the clearance δ between the pin and the bushing unchanged. Since the link L1 pulled by the spring or the like is moved to follow the pin (so that the pin is not moved alone by an amount of clearance δ), the parallelism between the stationary and movable platen is not degraded.