PURPOSE: To effectively carry out selective sealing by exposing openings of predetermined channels of honeycomb body through an end cap at one face and by exposing openings of the remaining channels of honeycomb body through end caps at other face.

CONSTITUTION: The end cap (2) comprising a green ceramic material is applied to each face (3, 4) of a green ceramic honeycomb body. Openings of predetermined channels (7) of the honeycomb body are exposed through the end cap (2) at one face (3) and openings of the remaining channels (7) of the honeycomb body are exposed through the end cap (2) at the other face (4). The composit honeycomb structure on which the end caps (2) are applied is fired. It is possible, as a result, to prepare practically as well as effectively the ceramic honeycomb structure of which inlet face and outlet face of its channels are selectively and integratively sealed by the end caps.