  In this letter we explore, both experimentally and theoretically, the
existence in the millimeter wave range of the phenomenon of extraordinary light
transmission though arrays of subwavelength holes. We have measured the
transmission spectra of several samples made on aluminum wafers by using an AB
Millimetre Quasioptical Vector Network Analyzer in the wavelength range between
4.2mm to 6.5mm. Clear signals of the existence of resonant light transmission
at wavelengths close to the period of the array appear in the spectra.
