Developing device and image forming apparatus

A developing device, comprising:

• a development container that contains therein toner to be supplied to an image carrier;
• a toner carrier that is rotatably supported in the development container and that supplies the toner contained in the development container to the image carrier in a facing region between the toner carrier the image carrier;
• and
• a regulation blade that contacts the toner carrier on an upstream side of the facing region in a rotation direction of the toner carrier and that regulates a thickness of a layer of the toner carried on the toner carrier,
• wherein
• the regulation blade is formed of a metal material polished in a direction same as a toner moving direction in a contact region between the regulation blade and the toner carrier such that an arithmetic average roughness of a surface of the regulation blade is 0.3 μm or less.