An image forming apparatus comprising: a rotatable image bearing member; a plurality of developing means (18, 18a to 18d) each having a rotatable toner bearing member (182, 182a to 182d), the toner bearing member being arranged to come into contact with a surface of the image bearing member and supply toner to an electrostatic latent image formed on the surface; a rotatable developing-means support member arranged to integrally support the plurality of developing means and rotate so as to cause the toner bearing members to sequentially come into and out of contact with the surface of the image bearing member; a drive transmission member provided in a main apparatus body and arranged to transmit a rotational driving force to each toner bearing member so as to rotate the toner bearing member; and a coupling member provided in each developing means and arranged to engage with the drive transmission member so as to transmit the rotational driving force from the drive transmission member to the toner bearing member, wherein the drive transmission member and the coupling member are engageable with each other before the toner bearing member comes into contact with the surface of the image bearing member; characterized in that the image forming apparatus comprises controlling means arranged to control the rotation of the developing-means support member such that, when the toner bearing member (182, 182a to 182d) is to be brought into contact with the image bearing member by rotating the developing-means support member, the controlling means temporarily stops the rotation of the developing-means support member at a position where the coupling member and the drive transmission member are engageable with each other, allows the coupling member and the drive transmission member to engage with each other so that the toner bearing member is set in a rotating state, and subsequently rotates the developing-means support member so as to bring the toner bearing member (182, 182a to 182d) into contact with the surface of the image bearing member. a rotatable image bearing member; a plurality of developing means (18, 18a to 18d) each having a rotatable toner bearing member (182, 182a to 182d), the toner bearing member being arranged to come into contact with a surface of the image bearing member and supply toner to an electrostatic latent image formed on the surface; a rotatable developing-means support member arranged to integrally support the plurality of developing means and rotate so as to cause the toner bearing members to sequentially come into and out of contact with the surface of the image bearing member; a drive transmission member provided in a main apparatus body and arranged to transmit a rotational driving force to each toner bearing member so as to rotate the toner bearing member; and a coupling member provided in each developing means and arranged to engage with the drive transmission member so as to transmit the rotational driving force from the drive transmission member to the toner bearing member, wherein the drive transmission member and the coupling member are engageable with each other before the toner bearing member comes into contact with the surface of the image bearing member; characterized in that the image forming apparatus comprises controlling means arranged to control the rotation of the developing-means support member such that, when the toner bearing member (182, 182a to 182d) is to be brought into contact with the image bearing member by rotating the developing-means support member, the controlling means temporarily stops the rotation of the developing-means support member at a position where the coupling member and the drive transmission member are engageable with each other, allows the coupling member and the drive transmission member to engage with each other so that the toner bearing member is set in a rotating state, and subsequently rotates the developing-means support member so as to bring the toner bearing member (182, 182a to 182d) into contact with the surface of the image bearing member.