To machine steel materials or the like of small size.

A bending device 1 is made up of a pump unit 3, a bender unit 5, and a connecting pipe 6 for connecting both the units 3, 5. The pump unit 3 is set to an operating device 2 so that it can be loaded and unloaded, and the pump unit 3 is driven by the operating device 2. A stationary die 16 and a moving die 20 are provided in the bender unit 5. The moving die 20 is driven by a piston 9 operated by the pressurized oil fed from the pump unit 3. Since the bender unit 5 is located apart from the operating device 2, a steel material 4 can be bent into a frame body or the like of small size.