To provide an inexpensive easy-to-produce chip for electrophoresis, a method for the production thereof, and a method for analyzing a substance.

The chip for electrophoresis comprises a tabular covering member 1, a tabular intermediate member 2 and a tabular base member 3. The tabular intermediate member has a narrow groove-shaped through hole 6 and liquid pool part forming through holes 5a, 5b provided at both the ends thereof. The tabular covering member has liquid pool part forming through holes 4a, 4b which form a liquid pool part together with the liquid pool portion forming through holes. Openings of the narrow groove-shaped though hole are each closed by the tabular covering member and the tabular base member to form capillaries. In the production method, the tabular covering member, tabular intermediate member and tabular base member are joined to each other. The analysis method employs the chip for electrophoresis.