In an image-forming device, each of the N chargers charges the opposed photoconductor with a discharge. The voltage applying unit applies voltages to the N chargers, individually. The abnormal discharge detecting unit detects an occurrence of an abnormal discharge at least one of the N chargers. The voltage detecting unit detects first voltages applied to the N chargers before the occurrence of the abnormal discharge is detected, and second voltages applied to the N chargers after the occurrence of the abnormal discharge is detected. The calculating unit calculates a difference between the first voltage and the second voltage for each of the N chargers. The identifying unit identifies one charger as a charger at which the abnormal discharge is occurring. The difference between the first voltage and the second voltage applied to the one charger is the greatest among the differences.