We put forward the concept of femtosecond laser speckles and studied twelve speckle patterns produced by four aluminium sheets with different surface roughness under illumination of three laser sources of one continuous wave laser and two other femtosecond pulsed lasers with FWHM widths of 36fs and 12fs, respectively. The femtosecond laser speckles are different from the conventional speckles in that femtosecond pulsed laser contain ultra-wide spectral contents. We explain the reason that makes femtosecond laser speckles different from conventional speckles. The relationship between speckle contrast and bandwidth of femtosecond laser is established, which well explains the experimental speckle contrast of the twelve speckle patterns.