This invention provides a plugging method, for a ceramic honeycomb body, that does not create clearance in plug members closing cell end portions. To produce a ceramic honeycomb body 5 having a large number of cells 55 partitioned by partitions 51 and cell end portions 50 plugged by plug members, end faces of the ceramic honeycomb body are immersed in a plug member slurry 1 while the cell end portions 50 not provided with the plug member are covered with a masking material 90, and are then dried and heated. The plug member slurry 1 contains ceramic particles, a foaming material and water or an oil solvent.