The above description of the structure and operation of the Muscle Fatigue Simulator was necessarily presented in an abridged fashion (a more complete description to be found in the report (3). The main goal of the construction of the model was creation of a system simulating the changes occurring in the EMG signal under the impact of local muscle fatigue. The performed verification of the model in the aspect of time, frequency and dynamic changes of simulated parameters confirmed simulating faithfulness of the model and thereby the initial assumptions and the general idea of the model may be considered correct. The muscle fatigue simulator has the capability to display some changes occurring in myoelectric signals during fatiguing contractions, and it is believed to have a great merit in demonstration of the signal processes within the muscle. For that reason, the Muscle Fatigue Simulator can be of use in teaching and in demonstration of particulars of the myoelectric signal during isometric contraction. It may also be used in instrument calibrating and in checking the operation of the EMG-signal measuring and analysing equipment applied in ergonomic studies.