A development device includes a developer carrier configured to carry on a surface thereof a developer, the developer carrier being disposed to face a latent image carrier, a developer tank having the developer carrier, a developer container configured to house the developer to be supplied to the developer tank, the developer container being connected to the developer tank through a partition having an opening, and a developer carrier member configured to carry the developer in the developer container, the developer being supplied to the developer tank from the opening while being carried by the developer carrier member, and the amount of developer to be supplied to the developer tank from the opening being gradually increased in a developer carrying direction of the developer carrier member.