A blade for a rotor, such as a turbine rotor of a gas turbine engine, has a squealer tip comprising a peripheral wall which defines a cavity. Also, a porous material having high porosity and high strength, which is suitable as a base material for an electrolyte membrane of a solid polymer fuel cell, is provided and a high-performance fuel cell using such material is realized. A second interlayer insulating film is provided on the second region, and is thicker than the first interlayer insulating film. The first angular transport unit is adapted to receive bills from the currency handling device and transport bills to the first currency document receiving unit.