According to the present invention, an inter prediction method comprises the steps of: generating a merge candidate list for a block to be predicted, wherein the block is to correspond to a current prediction unit; deriving, on the basis of one of a plurality of merge candidates constituting the merge candidate list, motion information on the block to be predicted; and performing, on the basis of the derived motion information, a prediction on the block to be predicted so as to generate a prediction block corresponding to the current prediction unit.