A simulation device calculates a detection number of electrons generated by charged particles radiated to a sample by a simulation and generates a simulation image of the sample. The simulation device holds penetration length information (272) in which incidence conditions of the charged particles and a penetration length are associated with each other, sample configuration information (271) which shows a configuration of a sample, and emission electron number information in which the incidence conditions of the charged particles and an emission electron number are associated with each other. The simulation device calculates the number of electrons emitted from a predetermined incidence point, on the basis of incidence conditions at the predetermined incidence point, the penetration length information (272), the sample configuration information (271), and the emission electron number information.