To provide a fluid streamline control device, easily manufactured and reduced in cost.

This fluid streamline control device is formed of a plate material having a predetermined thickness, and provided with two or more ring-like spacers formed by half-striking the plate material to form a pair of a projection and a recessed part on both surfaces thereof and two or more net-like streamline bodies having an outside diameter substantially equal to that of the spacer. A predetermined number of spaces are stacked with the projections and recessed parts fitted to each other to form a spacer block, and the spacer block and the streamline bodies are alternately assembled. Further, the streamline bodies are provided with cutout parts or hole parts formed in positions corresponding to the projections of the spacers, and assembled to the spacer block with the projections of the spacers inserted in the cutout parts or the hole parts.