To provide a safe working base capable of attaching a handrail, simply performing holding and detaching and safely performing lifting and lowering.

The holding device A of a handrail provided on a support 5 or the like and detachably holding a horizontal handrail 6 comprises a hook- like member 1 and a rod-like member 2. Both the members 1, 2 fix one end side to the support 5 or the like, are rotatable in a vertical face, at the normal time, the other end side of the hook-like member 1 is obliquely upward directed, the other end side of the rod-like member 2 is obliquely downward directed, and they are brought into contact with each other in a state where the other end side of the rod-like member 2 is obliquely downward extended from the other end side of the hook-like member 1.