A device for generating electricity by friction and a manufacturing method thereof. The device comprises a first substrate and a second substrate arranged oppositely, and a plurality of elastic columns arranged between the first substrate and the second substrate to support them. A surface of the first substrate facing the second substrate is provided with a first conductive electrode and an insulating polymeric membrane layer which are stacked. A surface of the second substrate facing the first substrate is provided with a second conductive electrode. At least one surface of the two opposite surfaces of the second conductive electrode and the insulating polymeric membrane layer is formed into a surface with a concave-convex structure. The friction area between the second conductive electrode and the insulating polymeric membrane layer can be increased upon relative movement between the first substrate and the second substrate.