The current distribution in a 1.2-kW PEMFC stack has been investigated using a triaxial magnetic sensor probe with the objective of determining the operating state of the PEMFC. The results show that the current distribution tended to concentrate on the underside of the cell. Current distribution was different in each cell because each cell had a different performance. In order to evaluate the performance of each cell, the I-V curve based on a model formula was calculated using the voltages obtained for each cell. Three cells having different cell performances were chosen and the relationship between the cell performance and the current distribution in the cell was evaluated. The results indicated that the standard deviations of current densities in the first and second cells were greater than that in the last one.