An electroencephalogram electrode unit for small animals for maximally detecting the EEG signals from the limited brain surface space of small animals is disclosed. The electroencephalogram electrode unit 1 for small animals includes: a base 2 that covers the scalp or brain surface of a small animal and has a plurality of through holes； and a plurality of electrodes 3. Each of the plurality of electrodes 3 is inserted into each of the plurality of through holes 2a, and each of the plurality of electrodes 3 is equipped with an insulating tube 4, an electrode section 6 disposed within the tube 4, an extraction conducting wire 7 that is connected to the electrode section 6 and extracts the EEG signal to outside, and a paste 8 that is filled within the tube. The tube 4 is installed in the through hole 2a in a manner of standing upright from the scalp or brain surface, and the electrode section 6 is formed in the form of a wire and is disposed, in a manner of standing upright from the scalp or brain surface, within the paste 8 filled within the tube 4.
