To provide a table top-type water tank which is, although the water tank is small-sized, compactly furnished with all of the various kinds of necessary units such as a heater, a pump, a lightening equipment or the like which a large-scale water tank is furnished with and even a beginner easily can perform maintenance for, and which is completely free from water leakage, can be easily placed on a table and is most suitable for an interior equipment.

A water tank section 12 and a mechanical section 13 are integrally formed out of a synthetic resin. A cartridge-type filter material case 3 storing a filter material in it is placed in the mechanical section 13 in a detachable manner, and a dropping board 6 formed in a shape having a number of pipe- shaped projecting parts 6d protruding upward and downward is placed on the filter material. A covering body 8 in which electrical parts are integrally stored is placed over the water tank 2 so that the electrical parts are separated from water.