In a cross section perpendicular to a rotational axis of a first image bearing member, when a common tangential line between the first image bearing member and a second image bearing member on an intermediary transfer belt side is a rectilinear line L, a rectilinear line passing through a rotation center of the first image bearing member and a rotation center of a first transfer member is a rectilinear line P, and a rectilinear line passing through an intersection point between the rectilinear line P and the first image bearing member and perpendicular to the rectilinear line P is a rectilinear line Q, an electrode member is constituted so that the contact portion contacting an inner surface of the belt is positioned on a first image bearing member side than the rectilinear line L is and on a first transfer member side than the rectilinear line Q is.