In order to provide a high-performance electrophoresis chip and an electrophoresis unit having the same that can restrain the diffusion of sample at an intersection between the electrophoresis groove and the sample introduction groove and prevent decrease in contrast and decrease in resolution, an electrophoresis chip is provided with a sample introduction groove, an electrophoresis groove, and a through hole. The sample introduction groove, the electrophoresis groove, and the through hole are formed on different substrates. In the electrophoresis chip, by combining the substrates, the sample introduction groove and the electrophoresis groove are located in different planes.