An image forming apparatus comprising: an image carrying member: a plurality of cartridges (40a, 40b, 40c, 40d) containing developing agent, each including an information storage means (41a, 41b, 41c, 41d) and a developing means for developing a latent image on the image carrying member with toner by applying a developing bias voltage; contact-type access means (142, 100) for accessing the information storage means of one of the plurality of cartridges (40a, 40b, 40c, 40d); rotatable holding means capable of rotatably holding the plurality of cartridges (40a, 40b, 40c, 40d) and of rotating so as to sequentially move the plurality of cartridges (40a, 40b, 40c, 40d) to an image forming position opposed to the image carrying member and to an access position different from the image forming position and opposed to the access means; and applying means for applying a developing bias voltage to a developing means of the cartridge (40a, 40b, 40c, 40d) opposed to the image carrying member at the image forming position, characterized in that the holding means is capable of stopping at a first stop position where the applying means applies a developing bias voltage while all of the information storage means (41a, 41b, 41c, 41d) of the plurality of cartridges (40a, 40b, 40c, 40d) are stopped at positions different from the access position (Pl) and one of the plurality of cartridges (40a, 40b, 40c, 40d) is stopped at the image forming position, and capable of stopping at a second stop position while all of the cartridges (40a, 40b, 40c, 40d) are stopped at positions different from the image forming position and one of the plurality of cartridges (40a, 40b, 40c, 40d) is stopped at the access position, and that, when the holding means stops at the second stop position, the access means (142, 100) is in contact with and accesses the information storage means of the cartridge stopped at the access position. an image carrying member: a plurality of cartridges (40a, 40b, 40c, 40d) containing developing agent, each including an information storage means (41a, 41b, 41c, 41d) and a developing means for developing a latent image on the image carrying member with toner by applying a developing bias voltage; contact-type access means (142, 100) for accessing the information storage means of one of the plurality of cartridges (40a, 40b, 40c, 40d); rotatable holding means capable of rotatably holding the plurality of cartridges (40a, 40b, 40c, 40d) and of rotating so as to sequentially move the plurality of cartridges (40a, 40b, 40c, 40d) to an image forming position opposed to the image carrying member and to an access position different from the image forming position and opposed to the access means; and applying means for applying a developing bias voltage to a developing means of the cartridge (40a, 40b, 40c, 40d) opposed to the image carrying member at the image forming position, characterized in that the holding means is capable of stopping at a first stop position where the applying means applies a developing bias voltage while all of the information storage means (41a, 41b, 41c, 41d) of the plurality of cartridges (40a, 40b, 40c, 40d) are stopped at positions different from the access position (Pl) and one of the plurality of cartridges (40a, 40b, 40c, 40d) is stopped at the image forming position, and capable of stopping at a second stop position while all of the cartridges (40a, 40b, 40c, 40d) are stopped at positions different from the image forming position and one of the plurality of cartridges (40a, 40b, 40c, 40d) is stopped at the access position, and that, when the holding means stops at the second stop position, the access means (142, 100) is in contact with and accesses the information storage means of the cartridge stopped at the access position. a plurality of cartridges (40a, 40b, 40c, 40d) containing developing agent, each including an information storage means (41a, 41b, 41c, 41d) and a developing means for developing a latent image on the image carrying member with toner by applying a developing bias voltage; contact-type access means (142, 100) for accessing the information storage means of one of the plurality of cartridges (40a, 40b, 40c, 40d); rotatable holding means capable of rotatably holding the plurality of cartridges (40a, 40b, 40c, 40d) and of rotating so as to sequentially move the plurality of cartridges (40a, 40b, 40c, 40d) to an image forming position opposed to the image carrying member and to an access position different from the image forming position and opposed to the access means; and applying means for applying a developing bias voltage to a developing means of the cartridge (40a, 40b, 40c, 40d) opposed to the image carrying member at the image forming position, characterized in that the holding means is capable of stopping at a first stop position where the applying means applies a developing bias voltage while all of the information storage means (41a, 41b, 41c, 41d) of the plurality of cartridges (40a, 40b, 40c, 40d) are stopped at positions different from the access position (Pl) and one of the plurality of cartridges (40a, 40b, 40c, 40d) is stopped at the image forming position, and capable of stopping at a second stop position while all of the cartridges (40a, 40b, 40c, 40d) are stopped at positions different from the image forming position and one of the plurality of cartridges (40a, 40b, 40c, 40d) is stopped at the access position, and that, when the holding means stops at the second stop position, the access means (142, 100) is in contact with and accesses the information storage means of the cartridge stopped at the access position.