Environmental pollution is attracting increasing attention, and soil contamination is one of them. Soil contamination includes heavy metals and organic pollutants that pose a hazard to humans and living organisms. Various soil assessment technologies are available to detect such soil contamination. However, these technologies are costly, and thus, low-cost soil-sensor technologies are needed. Microbial fuel cells (MFCs) can be used as low-cost soil sensors. In this experiment, a box-type MFC with a ceramic separator is proposed. This is a low cost, compact design. The soil-sensing performance of the Box MFC was evaluated. The amount of organic matter in the soil was changed, and the corresponding voltage of the MFC was measured. Changes in the voltage and its reproducibility with changes in the soil were observed. From these results, the potential of Box MFC as a soil-sensing technology was demonstrated.