Lifting and Lowering Device for Construction Machine

A pair of right and left supporting bases () provided on a sidewalk () of a revolving body () and both right and left sides () of a movable ladder () are connected by trajectory restricting members () in a swingable manner. In positions of the left supporting base () which are apart from each other, main body base ends (and ) of first and second hydraulic cylinders ( and ) are pivotally supported, and rod tip ends (and ) of the respective hydraulic cylinders ( and ) are pivotally supported in a common position of the left side () of the movable ladder (). By operating the first and second hydraulic cylinders ( and ) in directions reverse to each other (extension and retraction), in-common pivotally supported parts (and ) are moved, thereby switching a position of the movable ladder () between an extended position and a retracted position.