The capillary electrophoresis device using one pressure-resistant syringe (125) is capable of automatically suctioning in polymer solution and injecting polymer solution into a capillary array (100). An electric hook (131) is installed for pulling up the syringe plunger on a push-in action type syringe (125). A check valve (124) is inserted between a polymer bottle (123) and syringe to prevent solution from flowing back into the polymer bottle. As a result, one syringe portion of polymer solution can be suctioned and injected, a large volume of polymer solution can be continuously used and device processing capability is improved.