Resin molding device and method for manufacturing resin molded article

The invention provides a resin molding device capable of manufacturing a resin molded product with high precision. The resin molding apparatus includes: a lower mold on which a substrate is placed; the upper die forms a die cavity by a side block and a die cavity block, and the die cavity block is arranged in a manner of being capable of lifting up and down relative to the side block; the clamping mechanism is used for clamping the lower die and the upper die; a transfer mechanism for supplying a resin material to the cavity through a plunger; and a control unit that performs a first final adjustment control for performing adjustment so that the clamping load generated by the clamping mechanism becomes a final clamping load after the mold cavity is filled with the resin material supplied from the transfer mechanism, and a second final adjustment control for performing adjustment so that the clamping load generated by the clamping mechanism becomes a final clamping load after the mold cavity is filled with the