Manufacturing method of plugged honeycomb structure

A manufacturing method of a plugged honeycomb structure, comprising:

• a honeycomb structure forming step of forming a pillar-shaped honeycomb structure having partition walls defining a plurality of cells which become through channels for fluid and extend from a first end face to a second end face;
• and
• a plugging step of forming plugging portions in end portions of the cells of the honeycomb structure formed in the honeycomb structure forming step,
• wherein in the plugging step, there is performed a press pouring operation of pressing one end face of the honeycomb structure into a plugging slurry stored in a bottomed tubular container to pour, under pressure, the plugging slurry into the cells of the honeycomb structure, and
• as the plugging slurry of the plugging step, there is used a slurry in which a yield point viscosity of a viscous fluidity is 600 Pa·s or more, a recovery viscosity is 300 Pa·s or more, and a high shearing viscosity is 200 Pa·s or less.