Measurement of activated materials and evaluation of activated areas of several types of accelerator facilities were studied for decommissioning planning from FY2017 to FY2020 under the contract of the Nuclear Regulation Authority. The research results were summarized in “Manual of Measurement and Evaluation of Activation for Decommissioning of Accelerator Facilities.” This manual consists of the classification of the activation area of accelerator facilities and the measurement and evaluation of the activation of concrete structures and metallic accelerator components in the decommissioning of accelerator facilities. This manual will be used for the decommissioning of accelerator facilities in Japan.