To provide a counterweight suppressed in weight and easily maintainable and inspectable, without deteriorating the aesthetic appearance in terms of design.

A construction machine, such as, a hydraulic shovel comprises a counterweight which is installed near the rear of an engine and in which an opening is formed for inspecting and maintaining the engine; an auxiliary weight, formed of a plurality of blocks which can be stored into and taken out of the space formed by the opening; a stopper for preventing the blocks from advancing and falling to the engine side through the opening; and a cover fitted detachably or openably to the outer surface of the opening.