To provide a water-saving cushion for a bath which saves water to be stored in a bathtub, is comfortable and is used as an auxiliary device for an aged person or physically disabled person, becomes a warmer by itself, and performs heat-retention for bathtub water.

The cushion is obtained by filling a rubber or plastic bag-shaped object with a filling material (Fig.1) (the bag-shaped object and the filling material having a shape following a weight added thereto in shape) or by integrating the external bag-shaped object with the filling material without separating them (Fig.2) (the materials also have a shape following a weight added thereto). The object is put into the bathtub, so as to demonstrate a water-saving effect for the portion of the volume. Besides, the problem is solved by using a material with a thermal insulation effect or a material which takes into consideration specific gravity with water, the appropriate following property to the weight, and elasticity.