Recycled resin is produced by a method including a dismantling/recovery step of dismantling products containing resin moldings and recovering the resin moldings, a removal step of removing unwanted matter including metal components from the resin moldings, a sorting step of discriminating the materials of the resin moldings, and a crushing step of crushing the resin moldings. The method further includes, prior to the crushing step, detecting the metal components, and, after the crushing step, separating out and thus removing metal remaining in crushed material.