To provide a mounting structure for simplifying the attachment/detachment of a diesel particulate filter without the removal or movement of a counter weight.

The mounting structure is for mounting a diesel particulate filter 6, which removes particulate matter in the exhaust gas of an engine, in a forklift. The forklift includes a vehicle body, a working device disposed at the front thereof, and a counter weight 4 disposed in the rear part of the vehicle body to accommodate 6. The diesel particulate filter 6 is detachably mounted to mountings provided inside the counter weight 4. An opening 4a is formed through the counter weight 4 and is large enough to allow the diesel particulate filter 6 to pass therethrough in the vertical direction.