EXHAUST GAS PURIFICATION SYSTEM FOR WORKING MACHINE

It is an object of the present invention to easily executing a careful work which is executed on the basis of an engine sound. An exhaust gas purification system of a working machine according to the present invention is provided with an engine 70 which is mounted to the working machine 140, an exhaust gas purification device 50 which is arranged in an exhaust system 77 of the engine 70, and renewing devices 70, 81, 82, 117 for burning and removing a particulate matter within the exhaust gas purification device 50. In the case that a clogged state of the exhaust gas purification device 50 is equal to or more than a prescribed level, the renewing devices 70, 81, 82 and 117 can be actuated. It is provided with renewal admittance input means 21 which allows an actuation of the renewing devices 70, 81, 82, 117, and rotating speed holding input means 27 for holding a rotating speed N of the engine 70 at a predetermined rotating speed Nm. In the case that a turn-on operation of the rotating speed holding input means 27 is carried out in a state in which an allowing operation of the renewal admittance input means 21 is carried out, a rotating speed holding motion of the engine 70 is executed in preference to an actuation of the renewing devices 71, 81, 82, 117.