To provide a cleaning device having a structure of a dropper-type circulation pump form, capable of easily removing and cleaning feces, etc., of ornamental fish while freely changing a suction amount by manual operation and suitable for cleaning an aquarium for freshly-hatched fish.

The cleaning device 1 for aquarium precipitate has two flow channels: one channel is a suction flow channel 2 having a flat suction port to widely suck precipitate 9 precipitated on a bottom face of the aquarium and having a precipitate reservoir 3 having a filter 8 in the flow channel; and the other channel is a discharging channel 6 having a backflow prevention valve 4 at a connection part with the suction side, and connected to bellows 5 for circulating water by pumping action. The precipitate 9 is filtered with the filter in the course of circulating through these two flow channels, precipitated in the precipitate reservoir 3 and removed. The precipitate reservoir 3 can be removed to enable washing of the precipitate reservoir 3 and the filter 8 after cleaning the precipitate. Stable manual operation such as adjustment of suction power and cleaning of a delicate part can be carried out by actuating the bellows 5 by gripping a handle 7 formed to a pistol-type to facilitate the operation.