A WR-1.5 band (500-750 GHz) waveguide 3rd order bandpass filter has been designed, fabricated, using SU8 photoresist technology, tested and presented. The filter is composed of three silver-coated SU8 layers, each of the same nominal thickness of 191 μm. This filter structure is based on three offset resonators. This novel structure is ideally suitable for the layered SU8 micromachining process. The filter exhibits a 53.7 GHz 3-dB bandwidth at a central frequency of 671 GHz. The median passband insertion loss is measured to be 0.65 dB and the return loss is better than 11 dB over the whole passband.