An image forming apparatus performing image forming operation to form an image on a transfer-receiving member, the image forming apparatus comprising: a rotatable photosensitive drum; a charging member configured to charge a surface of the photosensitive drum at a charging portion where the charging member faces the photosensitive drum; an exposure means for exposing the surface of the photosensitive drum charged by the charging member, to form an electrostatic latent image on the surface of the photosensitive drum; a developing member configured to develop the electrostatic latent image as a developer image by supplying a developer charged to normal polarity to the surface of the photosensitive drum; a transfer member configured to form a transfer portion by coming into contact with the photosensitive drum, and to transfer the developer image from the photosensitive drum to the transfer-receiving member at the transfer portion; a brush member configured to form a contact portion on a downstream side of the transfer portion and on an upstream side of the charging portion in a rotation direction of the photosensitive drum, and to come into contact with the photosensitive drum at the contact portion; a voltage application means for applying a voltage to the brush member; a driving means for rotationally driving the photosensitive drum; and a control means configured to control the voltage application means and the driving means, wherein, after the developer image formed on the surface of the photosensitive drum is transferred to the transfer-receiving member at the transfer portion, the developer remaining on the surface of the photosensitive drum is collected by the developing member, and wherein the control means is configured to perform control to make a direction of an electric field generated in a first area of the photosensitive drum forming the transfer portion during the image forming operation, relative to the voltage applied to the brush member in a state where the first area passes through the contact portion, different from a direction of an electric field generated in a second area of the photosensitive drum forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the photosensitive drum is rotated at a first speed to second operation in which the photosensitive drum is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation, and wherein the brush member takes a posture falling toward downstream in the rotation direction of the photosensitive drum during the first operation, relative to a posture of the brush member during the second operation. a rotatable photosensitive drum; a charging member configured to charge a surface of the photosensitive drum at a charging portion where the charging member faces the photosensitive drum; an exposure means for exposing the surface of the photosensitive drum charged by the charging member, to form an electrostatic latent image on the surface of the photosensitive drum; a developing member configured to develop the electrostatic latent image as a developer image by supplying a developer charged to normal polarity to the surface of the photosensitive drum; a transfer member configured to form a transfer portion by coming into contact with the photosensitive drum, and to transfer the developer image from the photosensitive drum to the transfer-receiving member at the transfer portion; a brush member configured to form a contact portion on a downstream side of the transfer portion and on an upstream side of the charging portion in a rotation direction of the photosensitive drum, and to come into contact with the photosensitive drum at the contact portion; a voltage application means for applying a voltage to the brush member; a driving means for rotationally driving the photosensitive drum; and a control means configured to control the voltage application means and the driving means, wherein, after the developer image formed on the surface of the photosensitive drum is transferred to the transfer-receiving member at the transfer portion, the developer remaining on the surface of the photosensitive drum is collected by the developing member, and wherein the control means is configured to perform control to make a direction of an electric field generated in a first area of the photosensitive drum forming the transfer portion during the image forming operation, relative to the voltage applied to the brush member in a state where the first area passes through the contact portion, different from a direction of an electric field generated in a second area of the photosensitive drum forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the photosensitive drum is rotated at a first speed to second operation in which the photosensitive drum is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation, and wherein the brush member takes a posture falling toward downstream in the rotation direction of the photosensitive drum during the first operation, relative to a posture of the brush member during the second operation.