An image forming apparatus comprising: an image bearing member to bear a latent electrostatic image; a charger to charge a surface of the image bearing member; an irradiator to irradiate the image bearing member with light to form the latent image; a developing device to develop the latent electrostatic image with a developing agent comprising toner to obtain a visible image; a transfer device to transfer the visible image to a transfer medium by a transfer bias applied to a transfer area between the image bearing member and the transfer member; a surface voltage detector to measure a first surface voltage of a surface portion of the image bearing member charged by the charger after the image bearing member has passed through the transfer area where the transfer bias is applied by the transfer device to satisfy a first set of current and/or voltage conditions and a second surface voltage of a surface portion of the image bearing member charged by the charger after the image bearing member has passed through the transfer area where the transfer bias is applied by the transfer device to satisfy a second set of current and/or voltage conditions different from the first set of current and/or voltage conditions in absolute value of a current or a voltage applied per unit of area of the surface of the image bearing member; and a life status determination device to determine a working life status of the image bearing member based on a comparison of the first surface voltage and the second surface voltage measured by the surface voltage detector, characterized in that the determined working life status describes whether the image bearing member has come to the end of its working life and/or describes a prediction about when the image bearing member comes to the end of its working life. an image bearing member to bear a latent electrostatic image; a charger to charge a surface of the image bearing member; an irradiator to irradiate the image bearing member with light to form the latent image; a developing device to develop the latent electrostatic image with a developing agent comprising toner to obtain a visible image; a transfer device to transfer the visible image to a transfer medium by a transfer bias applied to a transfer area between the image bearing member and the transfer member; a surface voltage detector to measure a first surface voltage of a surface portion of the image bearing member charged by the charger after the image bearing member has passed through the transfer area where the transfer bias is applied by the transfer device to satisfy a first set of current and/or voltage conditions and a second surface voltage of a surface portion of the image bearing member charged by the charger after the image bearing member has passed through the transfer area where the transfer bias is applied by the transfer device to satisfy a second set of current and/or voltage conditions different from the first set of current and/or voltage conditions in absolute value of a current or a voltage applied per unit of area of the surface of the image bearing member; and a life status determination device to determine a working life status of the image bearing member based on a comparison of the first surface voltage and the second surface voltage measured by the surface voltage detector, characterized in that