To provide a bubble generator generating bubbles floating in a lateral direction in an ornamental water tank, enhancing visual effect and healing effect for ornamental use, providing high advertising visual effect as a commercial water tank display.

In the bubble generator constituted of a pressure generater arranged in the ornamental water tank and a bubble generating unit, the pressure generater comprises a pressure generating mechanism by the reciprocation of a piston, a fluid pressure generating chamber, and a discharging hole arranged in a part of the wall face of the fluid pressure generating chamber, the bubble generating unit has a linear structure in which bubbles are discharged in a curtain shape, the bubble generater has a means forming bubbles moving in a lateral direction by the moving body of water intermittently discharged from the pressure generater passing through a linear bubble zone floating in a curtain shape of the bubble generating unit.