An image forming apparatus comprising: an image bearing member configured to bear a toner image; a transfer member configured to come into contact with the image bearing member and to transfer the toner image on the image bearing member onto a recording material; a cleaning brush configured to come into contact with the transfer member for electrostatically collecting the toner on the transfer member; a collecting roller configured to come into contact with the cleaning brush for electrostatically collecting the toner on the cleaning brush; and a power source configured to apply a cleaning bias with a constant current to the collecting roller for generating electrical fields both in a first contact portion and a second contact portion, the first contact portion being formed between the transfer member and the cleaning brush, the second contact portion being formed between the cleaning brush and the collecting roller; characterized by further comprising: an adjusting portion configured to adjusttneconstant current value to a predetermined current value, the predetermined current value being acquired in advance to satisfy a condition of both α > 90 % and β > 90%, α being defined as a ratio of an amount of toner collected by the cleaning brush to an amount of toner on the transfer member in the first contact portion, β being defined as a ratio of an amount of toner collected by the collecting roller to an amount of toner on the cleaning brush in the second contact portion, wherein a first penetration amount λ 1 of the transfer member to the cleaning brush and a second penetration amount λ 2 of the collecting roller to the cleaning brush are configured so as to satisfy a condition of α ≤ β. an image bearing member configured to bear a toner image; a transfer member configured to come into contact with the image bearing member and to transfer the toner image on the image bearing member onto a recording material; a cleaning brush configured to come into contact with the transfer member for electrostatically collecting the toner on the transfer member; a collecting roller configured to come into contact with the cleaning brush for electrostatically collecting the toner on the cleaning brush; and a power source configured to apply a cleaning bias with a constant current to the collecting roller for generating electrical fields both in a first contact portion and a second contact portion, the first contact portion being formed between the transfer member and the cleaning brush, the second contact portion being formed between the cleaning brush and the collecting roller; characterized by further comprising: an adjusting portion configured to adjusttneconstant current value to a predetermined current value, the predetermined current value being acquired in advance to satisfy a condition of both α > 90 % and β > 90%, α being defined as a ratio of an amount of toner collected by the cleaning brush to an amount of toner on the transfer member in the first contact portion, β being defined as a ratio of an amount of toner collected by the collecting roller to an amount of toner on the cleaning brush in the second contact portion, wherein a first penetration amount λ 1 of the transfer member to the cleaning brush and a second penetration amount λ 2 of the collecting roller to the cleaning brush are configured so as to satisfy a condition of α ≤ β. an adjusting portion configured to adjusttneconstant current value to a predetermined current value, the predetermined current value being acquired in advance to satisfy a condition of both α > 90 % and β > 90%, α being defined as a ratio of an amount of toner collected by the cleaning brush to an amount of toner on the transfer member in the first contact portion, β being defined as a ratio of an amount of toner collected by the collecting roller to an amount of toner on the cleaning brush in the second contact portion, wherein a first penetration amount λ 1 of the transfer member to the cleaning brush and a second penetration amount λ 2 of the collecting roller to the cleaning brush are configured so as to satisfy a condition of α ≤ β.