ELECTROPHORESIS DEVICE

To provide an electrophoresis method and an electrophoresis device which can reduce difficulty in operation while implementing sufficient staining. An electrophoresis device 10 includes a temperature gradient tank 12, a dispenser 14, a holder storage cabinet 16, a photographing unit 18, a PCR device 20, a chip rack 22, a chip disposal box 24, a DC power unit 26, a control unit 30, an arm 32, and a liquid feeder 34. A holder 100 and a cassette 150 removably attached to the holder 100 are put on the temperature gradient tank 12. The control unit 30 controls a carrying device 16a, the arm 32, the liquid feeder 34, the temperature gradient tank 12, an excitation light source 18a and a camera 18b in the photographing unit 18, and the DC power unit 26. The control unit 30 prestores a program for executing the control operation in its internal memory.