Sodium hydroxide is added to the coffee grounds to saponify and wash out the oil contained in them, and the remaining residue is glued with glutinous rice starch paste to make boards. No pollution is generated from production, use to disposal. After disposal, it can be composted, used as fuel or general garbage. It has no environmental burden and can fully utilize its residual value. It is anti-bending, biodegradable, and can be used to make daily necessities. Coffee soap has been tested and has