The present invention restrains adverse effects caused by refraction of a terahertz wave by a device under test when the terahertz wave is fed to the device under test for measurement. A container 10 contains at least part of a device under test 1 to be measured by a terahertz wave measurement device. The container 10 includes a gap portion 11 that internally arranges at least a part of the device under test 1, and an enclosure portion 12 that includes a first curved surface portion S1, and a second curved surface portion S2, and arranges the gap portion 11 between the first curved surface portion S1 and the second curved surface portion S2, thereby enclosing the gap portion 11. Moreover, a relationship n1