A charging device includes a charging roller, a cleaning roller, a pair of first supporting members, a pair of second supporting members and a pair of elastic members. The pair of first supporting members supports the charging roller in a rotatable manner. The pair of second supporting members supports the cleaning roller in a rotatable manner. The pair of elastic members is disposed between the first supporting members and the second supporting members, and pushes back the cleaning roller in a direction separate away from the charging roller. The second supporting member provided on one side in an axial direction of the cleaning roller has a roller-shift preventing part which blocks the cleaning roller. The elastic member provided on the one side in the axial direction pushes back the cleaning roller with force smaller than force of the elastic member provided on the other side in the axial direction.