A sheet feeder unit capable of separately supplying cut sheets of any thickness or characteristics without causing any residual deformation. The pile of cut sheets 11 are advanced one by one with a pair of feeding rollers 31 contacting thereto from one side thereof. A friction member 33 of various configurations is disposed at various positions for separating the outermost cut sheet 11 from the other sheets by the frictional force of contact generated therebetween when the friction member is backed away by the advancing cut sheet 11.