A service allocation determination device and service allocation determination method that can allocate a service to a slice without wasteful use of resources. In a BSS/OSS, a service request receiving unit receives service requirements and information indicating functions for implementing a service. An allocation determination unit, using the service requirements and slice information, determines whether to allocate the service to an existing slice or to a new slice. An allocation request unit makes a request to allocate the service to the slice determined by the allocation determination unit. In this case, because the BSS/OSS 10 determines whether to allocate the service to an existing slice or to a new slice based on the service requirements and the attribute of the existing slice, the service can be allocated to a slice without wasteful use of resources.