An object of the present invention is to provide titanium oxide granules that have a novel structure and have a characteristic of highly efficient decomposing capability, and a method of decomposing plastic and organic waste by using the granules. The present invention is completed based on confirmation that a method of decomposing plastic waste by using titanium oxide granules having a transition metal and/or a transition metal oxide, in particular copper, supported thereon enables decomposition of plastic waste at extremely high efficiency in a low-temperature region for a long period of time as compared to methods of decomposing plastic waste by using conventional titanium oxide granules.