Image Forming Apparatus

An image forming apparatus, which executes a developing operation for forming a developer image, and which forms an image comprising the developer image on a recording medium, the image forming apparatus comprising:

• an image carrier, on which an electrostatic latent image is formed;
• a developing housing that accommodates a developer for developing the electrostatic latent image into a developer image;
• a developer carrier, which is held by the developing housing, which carries the developer in the developing housing, and which supplies the developer to the image carrier;
• a developing bias supply part that supplies a developing bias to the developer carrier;
• a remaining quantity calculation part that calculates a remaining quantity of the developer in the developing housing;
• a deterioration grade storage part that stores a relationship between the remaining quantity of the developer in the developing housing and a deterioration degree of the developer caused by the developing operation;
• and
• a developing bias setting part that sets a value of the developing bias in accordance with the remaining quantity calculated by the remaining quantity calculation part and the relationship stored in the deterioration grade storage part.