Protective cover for a measuring instrument

A cover body (100), formed of an elastic member for covering a slider body (510) of a caliper, is provided with concavities and convexities (112) on the inner surface thereof and concavities and convexities (103) on the outer surface thereof. The cover body (100) is arranged so that it is easily deformed elastically in the portion of the concavities and convexities. When a shock is given from the outside, the portion of the concavities and convexities is deformed elastically to absorb the shock, hence the shock given to the slider body (510) is reduced. Accordingly, damage or failure hardly occurs on the measuring instrument.