In this letter, a miniaturized bandpass filter (BPF) is presented by utilizing the low-loss metal-integrated suspended meander line (MISML). All layers of the BPF are composed of metal, eliminating the dielectric loss to a large extent. Compared to the classical substrate-integrated suspended meander line (SISML), the proposed MISML achieves a higher Q value, thereby enabling low-loss and miniaturized transmission line (TL) with slow wave characteristics. Combining the concepts of MISML and λ /4 resonator to implement BPF topology, the circuit is effectively miniaturized. After extracting equivalent circuit parameters, a quadruplet BPF is designed and fabricated. The synthesized, simulated, and measured results are in good agreement. Moreover, the proposed BPF holds its advantages of high selectivity, ease of fabrication, and self-packaging.