The InfraRed Imaging Magnetograph (IRIM) is a high temporal resolution, high spatial resolution, high spectral resolving power, and high magnetic sensitivity solar two-dimensional narrow-band spectro-polarimeter working in the near infrared from 1.0 μm to 1.7 μm at Big Bear Solar Observatory (BBSO). It consists of an interference filter, a polarization analyzer, a birefringent filter, and a Fabry-Perot etalon. As the narrowest filter of IRIM, the infrared Fabry-Perot plays a very important role in achieving the narrow band transmission of ~ 10 pm and high throughput between 85% and 95% for the full wavelength range, maintaining wavelength tuning ability from 1.0 to 1.7 μm, and assuring stability and reliability. As the third of a series of publications describing IRIM, this paper outlines a set of methods to evaluate the near infrared Fabry-Perot etalon. Two-dimensional characteristic maps of the near infrared Fabry-Perot etalon, including the bandpass ▵λ, effective finesse Feff, peak transmission τmax, along with a free spectral range, flatness, roughness, and stability and repeatability were obtained with laboratory equipment. These measured results will benefit the optimization of IRIM design and observational mode of the future.