A robot hand member mounted on an arm unit of an industrial robot and a method of producing the same, wherein there are successively executed a step of laminating prepreg sheets each containing a reinforcing fiber on the outer peripheral surface of a core member having a predetermined shape in cross section, a step of heating the laminated prepreg sheets to a predetermined temperature to thermally set, to form a fiber reinforced plastic, and a step of removing the core member from the fiber reinforced plastic to obtain a hollow structure.