A construction machine comprising: an automotive vehicle body (2, 3); an engine mounted on said vehicle body (2, 3) in a laterally placed state extending in a left and right direction of said vehicle body (2, 3); a hydraulic pump provided on one side in a length direction of said engine, which is one side in a left and right direction of said vehicle body (2, 3); an exhaust pipe (26, 35) connected to an exhaust port of said engine; a first exhaust gas purifying device (16, 31) provided on an outlet side of said exhaust pipe (26, 35); a connecting pipe (19, 33) connected to an outlet port of said first exhaust gas purifying device (16, 31); and a second exhaust gas purifying device (21, 32) provided on an outlet side of said connecting pipe (19, 33); each of said first exhaust gas purifying device (16, 31) and said second exhaust gas purifying device (21, 32) has a cylindrical body (17, 22) having an axis (O1-O1, 02-02) extending in a front and rear direction of said vehicle body (2, 3), respectively, and arranged on an upper side of said hydraulic pump so as that each cylindrical body (17, 22) becomes parallel with each other, characterised in that: an inlet port (17A, 31A) of said first exhaust gas purifying device (16, 31) is provided on a side opposite to said engine by sandwiching said axis (O1-O1, 02-02) of said cylindrical body (17, 22) of said first exhaust gas purifying device (16, 31); and said exhaust pipe (26, 35) is constituted by a lateral pipe line extending in the left and right direction of said vehicle body (2, 3) on a front side of said first exhaust gas purifying device (16, 31) and having a bellows pipe (28, 36) for absorbing relative displacement between said engine and said first exhaust gas purifying device (16, 31) in the middle of said exhaust pipe (26; 35) and a bent pipe line bent rearward having a U-shape from a tip end side of said lateral pipe line and connected to said inlet port (17A, 31A) of said first exhaust gas purifying device (16, 31). an automotive vehicle body (2, 3); an engine mounted on said vehicle body (2, 3) in a laterally placed state extending in a left and right direction of said vehicle body (2, 3); a hydraulic pump provided on one side in a length direction of said engine, which is one side in a left and right direction of said vehicle body (2, 3); an exhaust pipe (26, 35) connected to an exhaust port of said engine; a first exhaust gas purifying device (16, 31) provided on an outlet side of said exhaust pipe (26, 35); a connecting pipe (19, 33) connected to an outlet port of said first exhaust gas purifying device (16, 31); and a second exhaust gas purifying device (21, 32) provided on an outlet side of said connecting pipe (19, 33); each of said first exhaust gas purifying device (16, 31) and said second exhaust gas purifying device (21, 32) has a cylindrical body (17, 22) having an axis (O1-O1, 02-02) extending in a front and rear direction of said vehicle body (2, 3), respectively, and arranged on an upper side of said hydraulic pump so as that each cylindrical body (17, 22) becomes parallel with each other, characterised in that: an inlet port (17A, 31A) of said first exhaust gas purifying device (16, 31) is provided on a side opposite to said engine by sandwiching said axis (O1-O1, 02-02) of said cylindrical body (17, 22) of said first exhaust gas purifying device (16, 31); and said exhaust pipe (26, 35) is constituted by a lateral pipe line extending in the left and right direction of said vehicle body (2, 3) on a front side of said first exhaust gas purifying device (16, 31) and having a bellows pipe (28, 36) for absorbing relative displacement between said engine and said first exhaust gas purifying device (16, 31) in the middle of said exhaust pipe (26; 35) and a bent pipe line bent rearward having a U-shape from a tip end side of said lateral pipe line and connected to said inlet port (17A, 31A) of said first exhaust gas purifying device (16, 31).