A developer collecting device includes a collecting box that accommodates developer discharged from a developing unit, the developing unit accommodating developer including toner and a carrier, the developing unit developing an electrostatic latent image on a development member using the toner in the developer; a guide cylinder that connects the developing unit and the collecting box to each other, the guide cylinder guiding movement of the developer discharged from the developing unit to the collecting box; a transporting member that is disposed in the guide cylinder and extends in a developer transport direction, the transporting member transporting the developer towards the collecting box by rotation of the transporting member; and a rotation controller that controls rotation speed of the transporting member in accordance with conditions that affect a capability of developing the electrostatic latent image on the development member.