Proposed are a functional improvement evaluation apparatus and a nerve cell culture apparatus of model animals capable of performing feedback control, even to mammalian model animals, based on biosignals in the same manner has humans based on a relatively simple configuration. The present invention comprises a biosignal detection unit which is mounted on a central side above an intended in vivo site of a mammalian model animal and/or a peripheral side below an intended in vivo site of a mammalian model animal, and detects a biosignal resulting from a biological activity of the model animal, a control unit which causes a driving source to generate power according to an intent of the model animal based on the biosignal detected by the biosignal detection unit, and a motion transmission mechanism which is connected to a holding part for holding a foot of each leg of the model animal, and transmits the power of the driving source to the holding part so that the holding part swings at a same or approximate trajectory as a natural walking motion pattern of the model animal, and the control unit controls the power of the driving source based on a swing state of the holding part connected to the motion transmission mechanism.