Adjusting a mold-clamping force by moving a fixing position of a toggle support (15) of a mold-clamping apparatus (10) so as to be close to a target mold-clamping force. Changing a mold protection position in accordance with an amount of movement of the toggle support (10). The adjustment of the mold-clamping force is performed based on a first mold-clamping force setting value that is acquired from a relationship between a push-in amount and a corresponding mold-clamping force that has been obtained by attaching a reference mold to the mold-clamping apparatus (10). The adjustment of the mold-clamping force may be performed based on a difference between a mold-clamping force detection value obtained by detecting an actual mold-clamping force and the target mold-clamping force by performing mold-clamping by using the first mold-clamping force setting value.
