Array-based electrochemical detection is useful for high throughput analysis. For the detection, a device containing many electrochemical sensors is utilized. However, it is difficult to incorporate many electrochemical sensors into a small device due to lack of space. In the present study, we developed a novel simple method to incorporate many sensors into a device. In the method, sensor electrodes with different sizes are connected with only single working electrode, and droplets with or without target redox compounds are put on sensors. To tag the addresses of the sensors, the electrode sizes are controlled. Electrochemical signals from the working electrode are digitally divided by data analyses based on the electrode sizes, so that digital electrochemical detection can be performed. The method is useful for high-throughput electrochemical analysis based on digital detection.