A working machine body includes a machine body having a front and a rear opposite to the front in a front-rear direction and an engine mounted in the machine body. A selective catalytic reduction catalyst is provided in the machine body and connected to the machine body and connected to the engine. A urea aqueous solution tank is to store a urea aqueous solution. The urea aqueous solution tank is connected to the selective catalytic reduction catalyst and provided in the machine body between the engine and the front of the machine body in the front-rear direction.