A novel millimeter wave substrate integrated waveguide(SIW) filter with compact configuration was presented.Its performance is improved apparently while the configuration is compacted.In the designed millimeter wave SIW filters,the length is reduced from 23.1mm of traditional filter to 12mm of novel filter.Measured results show that the stopband rejection of novel filters is more than 54dB,improved at least 12dB compared to the traditional filter with similar performance.The bandwidth of stopband with rejection better than 50dB has been expanded to more than 9GHz.It has a sharper transition characteristic at the upper sideband but still keeps the sharp transition characteristic at the lower sideband and low insertion loss,of the traditional SIW filter.