Catalytic device

A catalytic device comprising:

• a catalyst support that is formed by metal leaf-shaped flat plate and corrugated plate being stacked and rolled and supports a catalyst;
• and
• an outer cylinder that houses the catalyst support and supports the catalyst support with one end of the catalyst support made to face an upstream side of exhaust gas and another end of the catalyst support made to face a downstream side of the exhaust gas, wherein,
• the flat plate and the corrugated plate have a plurality of holes,
• in a flat state in which the flat plate and the corrugated plate are not yet shaped into the catalyst support, the plurality of holes form a plurality of first lines by aligning in a first direction that is parallel to a direction of an axis of the catalyst support and form a plurality of second lines by aligning in a second direction that is orthogonal to the first direction,
• a joint area between the flat plate and the corrugated plate is provided in a first upstream area including the one end of the catalyst support, and
• a joint area between the catalyst support and the outer cylinder is provided in a second upstream area including the one end of the catalyst support.