CONSTRUCTION MACHINE

To provide a construction machine including preferable maintenance performance of allowing bleeding from a hydraulic closed circuit in a short time.SOLUTION: A construction machine 100 includes: a hydraulic oil tank 30; a charge pump 12; charge flow channels 14, 19 for connecting a first upstream side flow channel 15, a second upstream side flow channel 16 to a discharge port of the charge pump 12; a first check valve 23a; a second check valve 23b; a bleeding channel 29 connected to the hydraulic oil tank 30; a first circuit switcher 27 capable of switching between circulation and shutoff between the first upstream side flow channel 15 and the bleeding channel 29; and a second circuit switcher 28 capable of switching between circulation and shutoff between the second upstream side flow channel 16 and the bleeding channel 29.SELECTED DRAWING: Figure 2 【課題】油圧閉回路内のエア抜きを短時間で行うことができる良好なメンテナンス性能を備えた建設機械を提供する。【解決手段】建設機械１００は、作動油タンク３０と、チャージポンプ１２と、第１上流側流路１５および第２上流側流路１６とチャージポンプ１２の吐出ポートとを接続するチャージ流路１４，１９と、第１チェック弁２３ａと、第２チェック弁２３ｂと、作動油タンク３０に接続されたエア抜き流路２９と、第１上流側流路１５とエア抜き流路２９との間の流通と遮断とを切換可能な第１回路切換器２７と、第２上流側流路１６とエア抜き流路２９との間の流通と遮断とを切換可能な第２回路切換器２８とを備える。【選択図】 図２