1. An interference check device comprising: a model-number upper-limit input circuit to which an upper limit number of geometric models that is allocated to a modeling target is input, the modeling target being a target of an interference check; a modeling process circuit that, when a cuboid that is capable of enclosing the modeling target is set as the modeling target as a model for an interference check, uses new geometric models that have a calculation cost per unit distance calculation smaller than the cuboid and that are in number equal to or less than the upper limit number of the geometric models to replace the cuboid with the new geometric models and models the modeling target; a model-candidate storage memory that stores, as model candidates, models in Which the new geometric models are used; a computation-amount upper-limit setting process circuit that sets a computation upper-limit amount that is an upper limit of a computation processing amount in calculation processing of the interference check, on a basis of information relating to the computation processing amount required for each process performed by a controller that controls the modeling target; a volume-model determination process circuit that extracts, from the model candidates, a model candidate on which a calculation processing of the interference check is capable of being performed with the computation processing amount equal to or less than the upper-limit amount, and determines the model candidate having a smallest model enclosure volume as the model for the modeling target from among extracted model candidates; and an interference check process circuit that performs to the interference check between models by using the model determined by the volume-model determination process circuit, and, if there is a possibility of interference, outputs an operation stop command, and, if there is no possibility of interference, outputs an operation continuation command.