Abstract: This paper presents the method of designing and fabricating 6-pole TeraHertz (THz) iris band-pass filter by adopting micromachining technology. Based on the existing process conditions, through analyzing the influence of process factors on electromagnetic property of filters, the process and designing parameters are mutually compromised to avoid sharp deterioration of device performance due to process factors so that the design can be optimized, and ultimately the integratable THz filter of small insertion loss and high reliability is obtained. By applying the processing methods including Inductively Coupled Plasma (ICP) etching, evaporating, electroplating gold and bonding, the single after-dicing micromachined filter with the volume of 24.0 mm 5.0 mm 1.66 mm is fabricated. The filter is fixed by applying tunable measurement clamp, and the power meter is adopted to test its power attenuation. Measurements results show that the center frequency of a 10.6% 3 dB fractional bandwidth is 141.5 GHz, and the power attenuation is less than 1 dB at 141.5 GHz, thus proving the effectiveness of the proposed processing method.