Provided is a server that executes: acquiring at least one deterioration characteristic calculation model of a storage battery based on a test; acquiring operation data on the storage battery after the test; acquiring a degree of deterioration of the storage battery in the operation data; inputting the operation data into the at least one deterioration characteristic calculation model to calculate at least one deterioration coefficient; inputting the operation data into a degree-of-deterioration calculation model for calculating a degree of deterioration of the storage battery to calculate a degree of deterioration using the at least one deterioration coefficient calculated; adjusting the at least one deterioration characteristic calculation model to calculate a degree of deterioration close to the degree of deterioration acquired; calculating at least one deterioration characteristic using the at least one deterioration characteristic calculation model adjusted; and outputting the at least one deterioration characteristic calculated.