A decoding method for decoding a binary signal of last position information, wherein the last position information indicates a position of a last non-zero coefficient in a predetermined order in a current block to be decoded; the binary signal includes (i) a first signal having a length smaller than or equal to a predetermined maximum length and does not include a second signal or (ii) the first signal having the predetermined maximum length and the second signal; and the decoding method comprises: first decoding (S402, S405) for arithmetically decoding each binary symbol included in the first signal using a context switched among a plurality of contexts according to a bit position of the binary symbol; second decoding (S404, S407) for arithmetically decoding the second signal using a fixed probability when the binary signal includes the second signal; and debinarizing the last position information from the decoded signal; characterized in that in the first decoding, a binary symbol at a last bit position of the first signal is arithmetically decoded using a context exclusive to the last bit position, when the first signal has the predetermined maximum length; and each of binary symbols at two or more bit positions other than the last bit position of the first signal is arithmetically decoded using a context common to the two or more bit positions. the last position information indicates a position of a last non-zero coefficient in a predetermined order in a current block to be decoded; the binary signal includes (i) a first signal having a length smaller than or equal to a predetermined maximum length and does not include a second signal or (ii) the first signal having the predetermined maximum length and the second signal; and the decoding method comprises: first decoding (S402, S405) for arithmetically decoding each binary symbol included in the first signal using a context switched among a plurality of contexts according to a bit position of the binary symbol; second decoding (S404, S407) for arithmetically decoding the second signal using a fixed probability when the binary signal includes the second signal; and debinarizing the last position information from the decoded signal; characterized in that in the first decoding, a binary symbol at a last bit position of the first signal is arithmetically decoded using a context exclusive to the last bit position, when the first signal has the predetermined maximum length; and each of binary symbols at two or more bit positions other than the last bit position of the first signal is arithmetically decoded using a context common to the two or more bit positions. first decoding (S402, S405) for arithmetically decoding each binary symbol included in the first signal using a context switched among a plurality of contexts according to a bit position of the binary symbol; second decoding (S404, S407) for arithmetically decoding the second signal using a fixed probability when the binary signal includes the second signal; and debinarizing the last position information from the decoded signal; characterized in that in the first decoding, a binary symbol at a last bit position of the first signal is arithmetically decoded using a context exclusive to the last bit position, when the first signal has the predetermined maximum length; and each of binary symbols at two or more bit positions other than the last bit position of the first signal is arithmetically decoded using a context common to the two or more bit positions.