PROBLEM TO BE SOLVED: To provide a sealed structure of lighting fixture assembly, improve a relative position accuracy of internal optical components, hold a high level water tightness between the lighting fixture assembly and a base under their fixed state and enable the lighting fixture assembly to be independently removed from the base when a replacement work is carried out while the base is being left.SOLUTION: When a ship's lamp 1 is attached to a hull 2, a base 3 is attached to the hull 2 with a screw 9. After O-ring 5 is installed at the base 3, a leg part 30 of a lamp body 28 is abutted against the O-ring 5 and a lighting fixture assembly 4 is mounted on the base 3. An inner peripheral thread 24 of an attachment 6 is fastened against an outer peripheral thread 18 of the base 3, the O-ring 5 is compressed with the leg part 30 and then the lighting fixture assembly 4 is fixed to the base 3 under a condition in which a water-tight state is held by the O-ring 5 between the base 3 and the lighting fixture
