PURPOSE: To move a working means to an objective structure with a small driving energy by providing a working means with a float for floating a main body to be loaded.

CONSTITUTION: A main body 41 is floated in the air by a floating gaseous He-charged float 42, and driving power such as air and booster is supplied from an air source of a moving vehicle 59 to the main body 41 through a cord and a hose 57. After the main body 41 comes close to an object structure 40, when a suction pad 53 of a leg 50 is pushed to the objective structure 40 by the operation of a floating auxiliary booster 49, the leg 50 is fixed, and positioned in the objective structure 40. A discriminating sensor unit (a kind of working means) 43 loaded on the main body 41 is driven so as to discriminate the generation of crack and peeling of the objective structure 40 with the sensor unit 43. After the discrimination, output of the booster 49 is reduced so as to lower the main body 41, and the suction pad 53 is removed from a surface of the objective structure 40, and the main body 41 is moved to a following discriminating position by the drive of a moving booster 45 through a caster.