An image coding method, comprising: splitting an input image signal into a plurality of coding units, and subtracting a prediction signal from the input image signal for each of the coding units, eventually generating prediction error signals of the respective coding units; splitting each of the coding units into a plurality of transform units, and performing transform and quantization on a corresponding one of the prediction error signals for each of the transform units, eventually generating quantization coefficients of the respective coding units, wherein each of the transform units corresponds to a corresponding one of leaf nodes in a tree structure, and each of the quantization coefficients includes a luminance quantization coefficient and a chrominance quantization coefficient; and coding pieces of management information and the quantization coefficients into the tree structure, wherein 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, and wherein, in the coding, for each of the at least one of the leaf nodes, a first flag corresponding to the at least one of the leaf nodes is coded after coding a second flag corresponding to the at least one of the leaf nodes (S123, S125), thereby generating a coded signal in which the 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; characterized in that in the coding a corresponding piece of the management information and a corresponding one of the quantization coefficients are coded within each of the leaf nodes (S123, S125, S133), eventually generating the coded signal in which the coded corresponding piece of the management information and the coded corresponding one of the quantization coefficients are arranged in succession within the each of the leaf nodes. splitting an input image signal into a plurality of coding units, and subtracting a prediction signal from the input image signal for each of the coding units, eventually generating prediction error signals of the respective coding units; splitting each of the coding units into a plurality of transform units, and performing transform and quantization on a corresponding one of the prediction error signals for each of the transform units, eventually generating quantization coefficients of the respective coding units, wherein each of the transform units corresponds to a corresponding one of leaf nodes in a tree structure, and each of the quantization coefficients includes a luminance quantization coefficient and a chrominance quantization coefficient; and coding pieces of management information and the quantization coefficients into the tree structure, wherein 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, and (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, and wherein, in the coding, for each of the at least one of the leaf nodes, a first flag corresponding to the at least one of the leaf nodes is coded after coding a second flag corresponding to the at least one of the leaf nodes (S123, S125), thereby generating a coded signal in which the 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; characterized in that in the coding a corresponding piece of the management information and a corresponding one of the quantization coefficients are coded within each of the leaf nodes (S123, S125, S133), eventually generating the coded signal in which the coded corresponding piece of the management information and the coded corresponding one of the quantization coefficients are arranged in succession within the each of the leaf nodes.