To provide a molding method of a biodegradable material which can mold a molding having the strength and shape stability needed as a buffer material for packaging from the biodegradable material of which the main raw material is the starch of corn or the like.

This molding method of a biodegradable material comprises a material-filling process wherein a biodegradable material 42 prepared by applying a hot-melt binder by coating on the surfaces of foamed beads of which the main raw material is starch is filled in an in-mold space formed by a fixed half 3 and a movable half 28, a material compressing process wherein the biodegradable material in the in-mold space is compressed thereafter in such a degree that air permeability is maintained, by narrowing further a gap between the fixed half 3 and the movable half 28, a material heating process wherein the binder is melted by heating the biodegradable material 42 by blowing hot air into the in-mold space, a material cooling process wherein the biodegradable material 42 is caked thereafter by blowing cool air into the in-mold space and an eject process wherein molding is taken out of the in-mold space by withdrawing the movable half.