PURPOSE: To provide a cushion capable of being easily attached to a seat of any type by a simple machine equipment in a state capable of being instantly attached to the frame of a car seat and a method for producing the same.

CONSTITUTION: Entangled coil springs 2 are embedded in a layer 1 of a swollen synthetic resin material by half or more. A dense polymer layer 3 is integrally bonded to the surface opposite to the protruding side of the coil springs 2 of the layer. A flexible thin layer 4 of a coating material is sticked to the outside surface of this layer 3 in a form protruding to a large extent from the layer 3. This protruding state is preliminarily calculated in order to fix a cushion to the proper support of a seat and, after corner parts 5 are cut off, the side parts 6 of the layer 1 are bent to be strongly attached to the support of the seat.