A foot shock circuit for fear memory researches based on the design of Fred A. Masterson (1982) Grid and Peripheral Shock Stimulation in 'Electrical Stimulation Research Techniques', Academic Press. Because it utilizes relatively high voltage, over 500 V, only qualified engineers should make it. A MATLAB code for an auditory cue-dependent fear conditioning is available in GitHub (https://github.com/yuichi-takeuchi/CueFearConditioning).