This paper describes the development of a low cost current follower, suitable for current measurements in the pico to micro-ampere range in general laboratory and field applications. The versatile instrument is designed for voltammetric measurements with ultramicroelectrodes, in a two-electrode cell configuration. The signal output can be monitored either by using an analog-to-digital converter or by a conventional electromechanical recorder. Performance tests in which the potential ramp and the signal current acquisition were performed using a digital-to-analog and analog to digital interface and an IBM-PC microcomputer are also described.