This paper presents the recent advancement of the ITER Blanket Remote handling system (BRHS), aimed at addressing the challenging in-vessel environment of ITER. Due to the combination of gamma radiation and recently identified in-vessel humidity, original design of the BRHS with plated carbon steels must be replaced with stainless steels design. The BRHS design was modified based on evaluation of the corrosion resistance of various metals in a humid environment under gamma ray irradiation, considering strength and manufacturability of stainless steels. Furthermore, authors have also found that maraging steel treated by a black chrome plating can withstand a cumulative dose of 1 MGy without corroding, enabling the use of maraging steel wrenches, which are essential for FW central bolt torquing. The feasibility of the remote maintenance equipment design, which partially utilizes ultra-high-strength steel while employing stainless steels for the entire system, was confirmed.