1. An apparatus for decoding a moving picture, the apparatus comprising: an entropy decoder configured to extract motion information and a quantized coefficients sequence from a received bit stream; an inverse scanner configured to restore a quantized transform block by inversely scanning the quantized coefficients sequence; an inverse quantizer configured to generate a transform block by inversely quantizing the quantized transform block using a quantization step size; an inverse transformer configured to generate a restored residual block by inversely transforming the transform block; an inter predictor configured to generate a prediction block of a current prediction block based on the motion information; and an adder configured to generate a restored block by adding together the restored residual block and the prediction block, wherein, when the current prediction block is encoded in a merge mode, the inter predictor generates a merge candidate list using an available spatial and available temporal merge candidate, determines a motion vector and a reference picture index of a merge candidate in the merge candidate list indicated by a merge index as a motion vector and a reference picture index of the current prediction block, and generates the prediction block of the current prediction block using the motion vector and the reference picture index of the current prediction block, wherein the temporal skip candidate includes a reference picture index set to 0 and a motion vector, wherein, when a size of the transform block is larger than a predetermined size, the quantized transform block is restored by inversely scanning the quantized coefficients sequence in the unit of subset, and wherein a scan pattern for scanning the plurality of subsets is same as a scan pattern for scanning quantized coefficients of each subset.