An image decoding method, comprising: decoding a coded signal to generate quantization coefficients and pieces of management information, the quantization coefficients each corresponding to a corresponding one of transform units, wherein each of the transform units corresponds to a corresponding one of leaf nodes in a tree structure, each of the quantization coefficients includes a luminance quantization coefficient and a chrominance quantization coefficient, the quantization coefficients and the pieces of the management information have the tree structure, the pieces of the management information include (i) respective pieces of split information each of which corresponds to a corresponding one of nodes in the tree structure and indicates whether or not a transform unit corresponding to the corresponding one of the nodes is to be further split, (ii) first flags each of which corresponds to at least one of the leaf nodes and indicates whether or not a luminance quantization coefficient corresponding to any of the at least one of the leaf nodes exists, and (iii) second flags each of which corresponds to at least one of the leaf nodes and indicates whether or not a chrominance quantization coefficient corresponding to any of the at least one of the leaf nodes exists, in the coded signal, for each of the at least one of the leaf nodes, a coded first flag corresponding to the at least one of the leaf nodes is arranged after the coded second flag corresponding to the at least one of the leaf nodes, and, in the decoding, for each of the at least one of the leaf nodes, the coded first flag corresponding to the at least one of the leaf nodes is decoded after decoding the coded second flag corresponding to the at least one of the leaf nodes, and performing inverse quantization and inverse transform on each of the quantization coefficients, eventually generating prediction error signals of the respective transform units; and adding at least one of the prediction error signals to a prediction signal for each of coding units each including the transform units, eventually generating decoded signals for each of the coding units; characterized in that the decoding includes decoding, for each of the leaf nodes, a coded piece of the management information and a coded quantization coefficient which are arranged in succession in the coded signal within the each of the leaf nodes. decoding a coded signal to generate quantization coefficients and pieces of management information, the quantization coefficients each corresponding to a corresponding one of transform units, wherein each of the transform units corresponds to a corresponding one of leaf nodes in a tree structure, each of the quantization coefficients includes a luminance quantization coefficient and a chrominance quantization coefficient, the quantization coefficients and the pieces of the management information have the tree structure, the pieces of the management information include (i) respective pieces of split information each of which corresponds to a corresponding one of nodes in the tree structure and indicates whether or not a transform unit corresponding to the corresponding one of the nodes is to be further split, (ii) first flags each of which corresponds to at least one of the leaf nodes and indicates whether or not a luminance quantization coefficient corresponding to any of the at least one of the leaf nodes exists, and (iii) second flags each of which corresponds to at least one of the leaf nodes and indicates whether or not a chrominance quantization coefficient corresponding to any of the at least one of the leaf nodes exists, (i) respective pieces of split information each of which corresponds to a corresponding one of nodes in the tree structure and indicates whether or not a transform unit corresponding to the corresponding one of the nodes is to be further split, (ii) first flags each of which corresponds to at least one of the leaf nodes and indicates whether or not a luminance quantization coefficient corresponding to any of the at least one of the leaf nodes exists, and (iii) second flags each of which corresponds to at least one of the leaf nodes and indicates whether or not a chrominance quantization coefficient corresponding to any of the at least one of the leaf nodes exists, in the coded signal, for each of the at least one of the leaf nodes, a coded first flag corresponding to the at least one of the leaf nodes is arranged after the coded second flag corresponding to the at least one of the leaf nodes, and, in the decoding, for each of the at least one of the leaf nodes, the coded first flag corresponding to the at least one of the leaf nodes is decoded after decoding the coded second flag corresponding to the at least one of the leaf nodes, and performing inverse quantization and inverse transform on each of the quantization coefficients, eventually generating prediction error signals of the respective transform units; and adding at least one of the prediction error signals to a prediction signal for each of coding units each including the transform units, eventually generating decoded signals for each of the coding units; characterized in that the decoding includes decoding, for each of the leaf nodes, a coded piece of the management information and a coded quantization coefficient which are arranged in succession in the coded signal within the each of the leaf nodes.