The machining technics affect the resonant frequency and transmission ratio of FSS (frequency selective surface). Effects on the transmission properties of FSS were explored by experiments to the machining method, surface conductivity and additional conductive coating under the same condition respectively, based on planar FSS of finite extent and PNA 8363B test system. The experimental results show that the resonant frequency of planar FSS is moved by the machining method, the edge burr of FSS cell may effect the property, and may also effect the transmission ratio for different incidence angles. FSS surface conductivity also effects transmission ratio of planar FSS, transmission ratio reduces with the increase of sheet resistance value. The transmission properties are hardly changed by the additional conductive coating.