A point cloud decoding device according to the present invention 200 includes: a geometry information decoding unit 2010 that decodes a first flag used to indicate whether or not to carry out inverse quantization of position information from a bit stream; and a tree synthesizing unit 2020 that sets a value of NodeQp to zero in a case where the first flag indicates that the inverse quantization of the position information is not carried out, the NodeQp being used as a quantization parameter for each node.