An image forming unit includes an image bearing member. A transfer member
transfers a toner image on the image bearing member to a record member. A
cleaning member cleans toner adhered onto the transfer member. A toner
container contains toner cleaned by the cleaning member. A toner sensor,
which is positioned at a center area of said toner container in a
direction orthogonal to a moving direction of the image bearing member
and detects an amount of collected toner. A conveyance member conveys the
collected toner and includes first screws to convey toner to a position
corresponding to an area in which the first area is excluded from the
second area in a direction toward the detection position, and second
screws to convey toner to a position between said first screws and the
detection position in a direction opposite to the direction toward the
detection position.