A work machine comprising: an engine for the work machine; and an exhaust system for treating exhaust gas from the engine; wherein the exhaust system includes: a first exhaust system taking an almost cylindrical shape and including a first inflow port for the exhaust gas on one end side and a first discharge port for the exhaust gas on the other end side; a second exhaust system taking an almost cylindrical shape and including a second inflow port for the exhaust gas from the first exhaust system on one end side and a second discharge port for the exhaust gas on the other end side, the second exhaust system being connected on a downstream side of the first exhaust system; and a third exhaust system taking an almost cylindrical shape and including a third inflow port for the exhaust gas from the second exhaust system on one end side and a third discharge port for the exhaust gas on the other end side, the third exhaust system being connected on a downstream side of the second exhaust system, the first exhaust system and the third exhaust system are arranged to be in parallel with the respective one ends directed in the same direction, in a plan view, the second exhaust system is arranged with the other end side directed in the same direction as the respective one end sides of the first exhaust system and the third exhaust system to be in parallel with the first exhaust system and the third exhaust system between the first exhaust system and the third exhaust system, the second exhaust system in a side view being arranged above the first exhaust system and the third exhaust system, and the exhaust system is attached to the work machine so that in a plan view, the third exhaust port comes close to a center line extending in a front-rear direction of the work machine with the extending direction of the third exhaust system slanted relative to the extending direction of the center line, characterized in that, the work machine further comprising a bracket fixing the exhaust system in an engine room in which the engine is arranged, the bracket takes a mountain shape having right and left slopes that slant to become high from the right and left to a center of the work machine, the first exhaust system is fixed to any one of the right and left slopes, and the third exhaust system is fixed to the other of the right and left slopes. an engine for the work machine; and an exhaust system for treating exhaust gas from the engine; wherein the exhaust system includes: a first exhaust system taking an almost cylindrical shape and including a first inflow port for the exhaust gas on one end side and a first discharge port for the exhaust gas on the other end side; a second exhaust system taking an almost cylindrical shape and including a second inflow port for the exhaust gas from the first exhaust system on one end side and a second discharge port for the exhaust gas on the other end side, the second exhaust system being connected on a downstream side of the first exhaust system; and a third exhaust system taking an almost cylindrical shape and including a third inflow port for the exhaust gas from the second exhaust system on one end side and a third discharge port for the exhaust gas on the other end side, the third exhaust system being connected on a downstream side of the second exhaust system, a first exhaust system taking an almost cylindrical shape and including a first inflow port for the exhaust gas on one end side and a first discharge port for the exhaust gas on the other end side; a second exhaust system taking an almost cylindrical shape and including a second inflow port for the exhaust gas from the first exhaust system on one end side and a second discharge port for the exhaust gas on the other end side, the second exhaust system being connected on a downstream side of the first exhaust system; and a third exhaust system taking an almost cylindrical shape and including a third inflow port for the exhaust gas from the second exhaust system on one end side and a third discharge port for the exhaust gas on the other end side, the third exhaust system being connected on a downstream side of the second exhaust system, the first exhaust system and the third exhaust system are arranged to be in parallel with the respective one ends directed in the same direction, in a plan view, the second exhaust system is arranged with the other end side directed in the same direction as the respective one end sides of the first exhaust system and the third exhaust system to be in parallel with the first exhaust system and the third exhaust system between the first exhaust system and the third exhaust system, the second exhaust system in a side view being arranged above the first exhaust system and the third exhaust system, and the exhaust system is attached to the work machine so that in a plan view, the third exhaust port comes close to a center line extending in a front-rear direction of the work machine with the extending direction of the third exhaust system slanted relative to the extending direction of the center line, characterized in that, the work machine further comprising a bracket fixing the exhaust system in an engine room in which the engine is arranged, the bracket takes a mountain shape having right and left slopes that slant to become high from the right and left to a center of the work machine, the first exhaust system is fixed to any one of the right and left slopes, and the third exhaust system is fixed to the other of the right and left slopes.