Patent ID: 8494418

Claim:
A development device comprising: a developer storage part storing a developer while agitating the developer; a developer carrier having a carrying surface for carrying the developer, and a first magnet, the developer carrier receiving the developer on the carrying surface from the developer storage part while rotating in a predetermined direction, and supplying the developer to a predetermined image carrier; a magnetic member formed from a magnetic material, the magnetic member forming a predetermined regulatory gap with the carrying surface and arranged opposite to the first magnet; a second magnet arranged more upstream than the magnetic member when viewed from the rotating direction of the developer carrier, and having a magnetic pole of the same polarity as the first magnet; and a deterioration suppressing part suppressing deterioration of the developer that is transported to the regulatory gap along with the rotation of the developer carrier, wherein magnetic force of the second magnet is set greater than magnetic force of the first magnet, the magnetic member has an end surface that is opposed to the carrying surface to form the regulatory gap, the second magnet has an opposing surface that is opposed to the carrying surface, and the deterioration suppressing part is a developer layer formed from the end surface of the magnetic member to the opposing surface of the second magnet.