We report new estimates for the lower mass function of 5 young open clusters spanning an age range from 80 to 150 Myr .
In all studied clusters , the mass function across the stellar/substellar boundary ( \sim 0.072 \mbox { M } _ { \odot } ) and up to 0.4 \mbox { M } _ { \odot } is consistent with a power-law with an exponent \alpha \simeq - 0.5 \pm 0.1 , i.e. , dN / dM \propto M ^ { -0.5 } .