Abstract: The invention relates to a method for inspecting an inside room of a ship and/or performing works therein, wherein the inside room is preferably a cargo tank, a sludge tank, a ballast tank or a cargo hold. The method comprises the following steps: a) inserting, through an opening preferably provided in a ceiling portion of the inside room, accommodating means (10; 100) for accommodating at least one person; b) attaching at least one rope (12) at an upper part of the inside room, wherein the at least one rope is attached at the upper part of the inside room i. manually by one or a plurality of climbing persons using climbing equipment, and/or ii. by means of a drone, and/or iii. by means of a pivotable rod; and c) moving the accommodating means up and down along the at least one rope for inspecting the inside room and/or performing works therein by at least one service person accommodated by the accommodating means.