An image forming apparatus provided with a conductive member to form an image on a sheet using a toner, the image forming apparatus, comprises: a voltage acquisition portion configured to acquire a biased voltage value as a voltage value by applying a bias to the conductive member; an environment sensor configured to output an environment condition measurement value representing an internal environment condition; characterized by a service life determination portion configured to transform the biased voltage value acquired by the voltage acquisition portion into a virtual voltage value appearing in the conductive member as the biased voltage value under a standard environment condition, in which the environment condition has a predetermined standard condition, on the basis of the environment condition measurement value output from the environment sensor, and determine a service life of the conductive member on the basis of the virtual voltage value; wherein the virtual voltage value is defined as: virtual voltage value = biased voltage value × first critical voltage value / second critical voltage value wherein the first critical voltage value is the biased voltage value appearing when the conductive member encounters a wear-out limitation, and the internal environment condition has a predetermined standard condition; and the second critical voltage value is the biased voltage value appearing when the conductive member encounters a wear-out limitation, and the internal environment condition has the same condition as that of the voltage measurement timing. a voltage acquisition portion configured to acquire a biased voltage value as a voltage value by applying a bias to the conductive member; an environment sensor configured to output an environment condition measurement value representing an internal environment condition; characterized by a service life determination portion configured to transform the biased voltage value acquired by the voltage acquisition portion into a virtual voltage value appearing in the conductive member as the biased voltage value under a standard environment condition, in which the environment condition has a predetermined standard condition, on the basis of the environment condition measurement value output from the environment sensor, and determine a service life of the conductive member on the basis of the virtual voltage value; wherein the virtual voltage value is defined as: virtual voltage value = biased voltage value × first critical voltage value / second critical voltage value wherein the first critical voltage value is the biased voltage value appearing when the conductive member encounters a wear-out limitation, and the internal environment condition has a predetermined standard condition; and the second critical voltage value is the biased voltage value appearing when the conductive member encounters a wear-out limitation, and the internal environment condition has the same condition as that of the voltage measurement timing. the first critical voltage value is the biased voltage value appearing when the conductive member encounters a wear-out limitation, and the internal environment condition has a predetermined standard condition; and the second critical voltage value is the biased voltage value appearing when the conductive member encounters a wear-out limitation, and the internal environment condition has the same condition as that of the voltage measurement timing.