WORK BENCH LEVELING DEVICE

PROBLEM TO BE SOLVED: To prevent a tilt of a work bench, causing uncomfortableness to an operator when poor operation is generated caused by clogging of dust in a leveling valve. SOLUTION: This work bench leveling device is provided with a leveling selector valve 25 for allowing supply and discharge of hydraulic oil to a leveling valve 22 when control of the derricking operation of a boom is performed by an operating device 17 for performing control of the derricking operation of the boom, and for stopping supply and discharge of hydraulic oil to the leveling valve 22 when control of the derricking operation of the boom is not performed by the operating device 17. Moreover, when it is judged that the tilt angle of a work bench reaches the specified tilt angle by an angle detector 31 for detecting the tilt angle of the work bench, the switching operation of the leveling selector valve 25 is performed regardless of the operation of the operating device 17, and supply and discharge of hydraulic oil to the leveling valve 22 is stopped.