To provide a sock which does not spoil the beauty of the external appearance and is easily and quickly attached/detached in slippers and sandals which are ordinary, commercially available and has no clamps, and it keeps the inner sole of the slippers and the sandals cleaned up by detaching/attaching and washing the sock easily without washing the main body of the slippers and the sandals which are easy to get dirty and hard to wash.

1. A sock (1) of slippers and sandals is formed of elastic materials, such as rubber, synthetic rubber, plastic, leather or the like. 2. Right/left edges at positions touching inner edges (4) of the sock (1) which are attached with an upper cover (5) of the slippers/sandals are partially formed projecting to an inner face (6) of the upper cover (5) extending from the insole (2) of the slippers/sandals.