Mixing device

An additive added upstream of a selective catalytic reduction device is easily gasified and precipitation of the additive is suppressed. This mixing device is provided with: a housing that surrounds a filter having a discharge part from which exhaust gas is discharged or a discharge part of a catalyst; an upper pipe section that is inclined with respect to the vertical direction so as to approach the discharge section toward the vertical lower side in a region inside the housing facing the discharge section, and that has an opening section that opens in the opposite direction of the discharge section; a lower pipe section that is bent from the lower end of the upper pipe section, is inclined with respect to the vertical direction so as to be separated from the blow-out section toward the vertical lower direction, and protrudes outward from the housing to be connected to a selective catalytic reduction device; and an injection device, which is attached to the housing, and which injects a liquid additive toward