Abstract: The present invention aims to provide an electrophoresis device which detects the presence or absence of foreign matter in a flow path 111. In order to solve the above problems, the electrophoresis device of the present invention is characterized by including a flow path 111 filled thereinside with a migration medium, a migration medium container which stores a migration medium, a liquid feeding mechanism which feeds the migration medium to the flow path 111, a photographing device 115 which photographs the flow path 111, and a control unit which analyzes an image of the flow path 111 photographed by the photographing device 115 and in that the control unit determines the presence or absence of the foreign matter in the flow path 111 on the basis of the image of the flow path 111.