To ensure a discharge of chip power or cutting water on the surface of a telescopic cover by allowing a partial cover of the telescopic cover to move reciprocally forward and rearward, rightward and crosswise in a smooth manner properly, on a same plane, in response to the movement of the moving mechanism of such as a main spindle of an industrial machine.

In response to movement of a moving mechanism 6, a center telescopic cover 2 expands and shrinks slidingly, and on the same plane, a side telescopic cover 3 also performs the similar action. In this case, a pantagraph also performs the similar action and the sliding and direct movement characteristics of the covers 2, 3 are improved. Simultaneously, with a blade fixed to the cover 2 and the cover 3, chips powder and cutting water are discharged to the outside without allowing them to flow into the covers 2, 3.