The reducing agent tank has a tank main body and a feed pipe. The tank main body stores a reducing agent to be supplied to an exhaust gas treatment device. The feed pipe protrudes from the tank main body. The feed pipe is provided to replenish the tank main body with the reducing agent. A support base supports a vessel for the reducing agent for replenishment of the reducing agent tank. The support base is variable in position between a developed position in which the support base is arranged at a greater distance from the tank main body than from the feed pipe in a direction of protrusion of the feed pipe from the tank main body in a plan view and a stored position in which the support base is stored in an exterior cover.