A developer agitating/conveying device having at least one partition wall disposed within a housing with a developer transfer port at the central portion thereof; a first agitating/conveying member disposed along the partition wall on one side of the partition wall for conveying the developer from the opposite end portions toward the central portion thereof, the first agitating/conveying member having a first helical blade and a second helical blade; and a second agitating/conveying member disposed along the partition wall on the other side of the partition wall for conveying the developer from the central portion toward the opposite end portions thereof, the second agitating/conveying member having a first helical blade and a second helical blade. The first and second helical blades provided on the first agitating/conveying member for helically wound in directions opposite to each other and are constructed such that their respective inner end half pitches overlap with a phase angle of 180 degrees relative to each other so as not to intersect each other.
