In a mold apparatus, guide pins are provided at a movable mold, and guide holes are formed in a fixed mold, and even when the guide pins are offset in an arbitrary direction perpendicular to a mold clamping direction, the guide holes can be fitted respectively to the guide pins, and can guide the movable mold 19A into a position where the movable mold coincides with the fixed mold. A holding device is provided at the movable mold, and this holding device holds the movable mold relative to a movable base in a manner to allow the movable mold to move in an arbitrary direction perpendicular to the mold clamping direction.