An upper unit of an injecting molding apparatus includes an ingot entry for introducing into the apparatus an ingot to be molded and an ingot heating chamber for heating the ingot supplied via the entry, and a lower unit includes a crusher for crushing the heated ingot and an injecting machine having an axially movable screw shaft for slurring and injecting the crushed ingot into a mold. The upper and lower units are interconnected via a flexible connector unit which is flexible in a vertical direction to allow the lower unit to vertically displace relative to the upper unit. By disengaging the connector unit from the upper unit, the lower unit can be disconnected from and laterally pivoted with respect to the upper unit to permit easy access to both the units. This displacement of the lower unit permits facilitated maintenance operations of the apparatus. A lower door provided for openably closing an ingot exit hole of the heating chamber is a vertically pivotable door that does not require a large operating space.