An image forming apparatus, includes: a plurality of image forming stations each including an electrostatic
latent image carrier, a static eliminator that eliminates charges on the electrostatic
latent image carrier, and a charging member that is arranged to face the electrostatic
latent image carrier while defining a specified gap; a bias applicator that collectively applies charging bias voltages including alternating-current components to the charging members provided in collective bias image forming stations, the collective bias image forming stations being at least two of the plurality of image forming stations; a
current sensor that collectively detects currents flowing in the charging members provided in the respective collective bias image forming stations; and a
detector that detects an
abnormal discharge in the gap between the electrostatic latent image carrier and the charging member based on a current detection result by the
current sensor, wherein the
detector selects one of the collective bias image forming stations as a selected image forming
station, and determines presence or absence of the
abnormal discharge in the gap between the electrostatic latent image carrier and the charging member in the selected image forming
station based on the current detection result by the
current sensor when the bias applicator applies the charging bias voltages to the charging members in the respective collective bias image forming stations while causing the static eliminator provided in the selected image forming
station to operate and causing the
static eliminators provided in the collective bias image forming stations other than the selected image forming station to stop operating.