A magnet manufacturing device includes a heater, a nozzle, a magnetic field application magnet and a stage. The heater heats a mixture of magnetic particles and a resin material. The nozzle has an internal flow passage that conducts the mixture while the resin material is molten. The nozzle has a discharge port which discharges the mixture and thereby forms each of a plurality of filaments. The magnetic field application magnet applies a magnetic field to the internal flow passage. The stage has a stage surface on which the plurality of filaments are placed. The discharge port is relatively movable with respect to the stage surface such that the plurality of filaments are stacked to form an arbitrary shape.