A sub-10 μm InGaAs (IGA) focal plane array (FPA), with cut-off wavelength of 2.6 μm has been developed. The pixel pitch is reduced significantly comparing with that of reported extended wavelength IGA FPAs. To verify the feasibility of technology, the performance of sub-10 μm IGA FPA was tested and compared with 30 μm pixel pitch IGA FPA, which was fabricated from the same epitaxial material. The sub-10 μm IGA FPA exhibits high performances in terms of dark current (0.45 nA @VR = 10 mV) and R0A (14.7 Ω·cm2) at room temperature. Its quantum efficiency can reach 63%. The comparable performances to 30 μm pixel pitch IGA FPA illustrate that the sub-10 μm IGA FPA fulfils the needs of large formats (>1 K×1 K) and high densities in extended wavelength IGA detectors.