To provide a fuel tank capable of effectively reducing flowing noise of fuel.

A three-dimensional net body 11 made of a synthetic resin and having a three-dimensional net structure is attached to almost an entire surface of a ceiling 5a inside the tank 1. The three-dimensional net body 11 effectively breaks and absorbs flow of fuel to prevent the flowing noise generated of the fuel, thereby facilitating the application of a resin tank made by blow-molding, wherein a separator is hardly provided. A waste material generated in manufacturing the resin tank can be used as the of the three-dimensional net body 11, to eliminate disposal of the waste material.