The simulation and experimental study of a bandpass frequency selective surface filter in terahertz (THz) range using double-layer modified complementary structures are conducted in this paper. The modified four-split complementary electric inductive capacitive (CELC) structure is introduced as the resonant cell of the filter. The primary design objective is to improve the filtering performances of double-layer complementary metamaterial structures built on intensified thickening quartz substrate. The bandpass filter centered at 0.28 THz is simulated, fabricated and measured. Experimental results from 0.1 to 0.6 THz measured by THz time-domain spectroscopy are in excellent agreement with simulation. The reformative CELC bandpass filter has the advantages of a low cost, low loss, steepness of skirts, out-of-band rejection, and etalon resonance rejection.