A bed cushion providing a soft feeling without bottomed feeling and providing a cushionability even against a small load and a durability, and a bed using the cushion; a forming die for cushion capable of smoothly and neatly releasing a product by reducing a sticky feeling and a blocking produced when releasing the cushion formed by using elastomer; the cushion, comprising thin-walled partition walls erected parallel with each other generally in a lattice shape in plan view, whereby a soft contact feeling near a water bed can be provided while preventing air blow noise from being produced by a user.