To solve a problem that it is well known that a worker retains one leg high for reducing a burden of the worker's lumbar in standing work at a certain place (washing in a kitchen and the like), however, there is no other way but placing a step close to the feet in an existing sink or the like, the user often stumbles over it or it obstructs the work and a storage place is also required when being non-used.

A footrest body/footrest is hung to a front face upper edge of the sink or the like by a hook-shaped support shaft or sucked to the front face of the sink, so as to be non-obstructive in a place close to the feet and so as to eliminate the need of a separate storage space.