An exercising device includes a base placed on a plane, a cover pivotally connected with the base, and an exercise apparatus mounted between the base and the cover. The cover has a side pivotally mounted on a side of the base. The cover is pivoted relative to the base to open or close a top face of the base. The exercise apparatus includes a leg working unit mounted on the base. Thus, the exercising device is stored easily and conveniently and is adapted to function as furniture. The exercising device also has a dustproof function.