Several metallic mesh Fabry-Pérot interferometers (FPI) are designed and manufactured to measure terahertz waves with wavelengths larger than 150 μm (that is less than 2 THz in frequency). Metallic meshes with five different structural parameters whose periods are less than 40 μm and linewidths are less than 10 μm are fabricated by employing optoelectronics micro-nano manufacturing technology. By using terahertz time-domain spectroscopy, the refractive indices of the meshes and the refractive finesses of the FPI in terahertz wave band are obtained. Results show that all the meshes can work well for the interesting wavelengths. In order to test the feasibilities of the FPI, a wavelength of 212 μm is measured. Results show good agreements with theory. Moreover, dependences on the polarization orientation of the terahertz waves and the parallelism of the FPI are also demonstrated, and it is found that the FPI is insensitive to the polarization of the terahertz waves while susceptible to the parallelism of the FPI.