To allow easy and sure attachment irrespective of a thickness of a side wall of a bath tub, and to prevent an upper attaching frame and a tightening screw therefor from being projected greatly.

This hand rail has the L-shaped a first and second attaching members 2, 3 comprising horizontal pieces 21, 31 and vertical pieces 22, 32. This hand rail attaching structure is provided with an attaching frame 20 for overlapping the horizontal pieces 21, 31 of the first and second attaching pieces 2, 3 and adjusting a space between the both vertical pieces 22, 32 to be fixed and fitted to a side wall of a bath tub, a tightening means 4 screwed in a tapped hole provided in the vertical piece 21 of the first attaching member 2 to sandwich and fix the side wall of the bath tub by a tightening plate 41 attached to a tip part and the vertical piece 32 of second attaching member 3, and a hand rail 5 or a knob 6/or the hand rail 5 and the knob 6 attached to the vertical piece 32 of the attaching frame 20.