A capsule (1) is described, for preparing infusion or soluble beverages, in particular coffee or milk or chocolate, comprising at least one containing body (2) made of a compostabile/biodegradabile and or material having at least one base (3) and at least one opening (4) opposite to the base (3) and adapted to be closed by least one cover (5), the containing body (2) comprising at least one internal volume (V) adapted to contain at least one substance to be infused or solubilized, the cover (5) being made by overlapping at least one first layer (5a) composed of at least one compostabile/biodegradabile and or polyester and of at least one second, insulating inert layer (5b) made of a compostabile/biodegradabile and or material, wherein the first layer (5a) is interposed between the second layer (5b) and the internal volume (V).