A picture coding method includes: performing a first derivation process for deriving a first merging candidate which includes a candidate set of a prediction direction, a motion vector, and a reference picture index for use in coding of a current block (S113); performing a second derivation process for deriving a second merging candidate (S115); selecting a merging candidate to be used in the coding of the current block from among the first and second merging candidates (S120); and attaching an index for identifying the selected merging candidate to the bitstream (S130); wherein the first derivation process (S113) is performed so that a total number of the first merging candidates does not exceed a predetermined number, and the second derivation process (S115) is performed when the total number of the first merging candidates is less than a predetermined maximum number of merging candidates.