Method of manufacturing ceramic honeycomb structure and device for forming through holes

A method of manufacturing a honeycomb structure and a through hole forming device used in the manufacture of the honeycomb structure are provided, in which the step of closing a part of the cell ends at an end surface of the honeycomb structure is rationalized. In closing a part of the cell ends at the end surface of a honeycomb structure body, a film is attached to the end surface of the honeycomb structure body in such a manner as to cover the cell ends. The portion of the film located at the cell ends to be closed is thermally melted or burnt off thereby to form through holes. The end surface is dipped in a slurry containing an end surface closing material, so that the slurry is caused to enter the cell ends by way of the through holes. After that, the slurry is hardened while at the same time removing the resin film.