An image-forming device includes an electrophotographic image-forming section, a receptacle, a detecting unit, a shielding member, a drive mechanism. The electrophotographic image-forming section transfers developer onto a recording sheet to form developer image thereon. The receptacle collects developer not transferred onto the recording sheet. The receptacle includes a detection portion. The detecting unit detects light passing through the detection portion. The shielding member is movably disposed in the detection portion to move between a first position blocking the light to be detected by the detecting unit and a second position allowing the light to pass through the detection portion. The drive mechanism moves the shielding member between the first position and the second position in a direction different from a vertical direction.