To provide an aircraft strength testing apparatus that, using a curved specimen, can produce a desired stress safely and quickly by reliably applying an internal pressure, and moreover allows any resulting damage to be reliably observed. A testing apparatus 1 that applies an internal pressure, equivalent to a differential pressure between the outside and the inside of a section to be tested of a fuselage of an aircraft, to a curved specimen 10 corresponding to the section to be tested, includes: a pressure vessel 22 between which and the specimen 10 a cavity 23 is formed; and rods 25 that restrain the specimen 10 against the internal pressure. The pressure vessel 22 faces the outer side of the specimen 10. By reducing the pressure inside the cavity 23, an internal pressure is applied to the specimen 10.