Production process of high porosity closed cell type metal foam is developed using a hydrogel binder. Using this process, the stainless steel foam is produced with its porosity more than 98 %. However, we need to use fine metal powder to produce high porosity metal foam, and as the result, the production cost of the foam is increased. Therefore, the metal foams are produced using different grain size powders and their foam properties are compared with each other. As the result, finer powders should be used for producing high porosity metal foam. However, relatively coarse powder can be used for producing 95 % porosity metal foam, decreasing the production cost of the foam. This cost reduction can expand the applications of this material.