In the high flux test module of IFMIF using gaseous helium as coolant, temperature control with high accuracy is required for irradiated specimens and proper flow control is indispensable for this purpose. We have proposed a porous-type manifold which is used as a flow distributor of coolant entering an irradiation region of the module. The manifold is comprised of a straightener part with porous plates located upstream of the irradiated region and a bifurcation part into four cooling channels just before entering the region. In this study, we manufactured a mock-up of the manifold and performed fluid flow experiment by varying the porous plates inserted in the straightener part. The most controversial part of development of the manifold is whether velocity profiles in the four channels after passing the manifold become the same. In the experiment, distribution of the flow rate into the four channels was sufficiently achieved, but this was considered due to not the porous plates but a geometrical configuration of the bifurcation part. The porous plates contributed to the velocity profile. The velocity profile was remarkably changed by the porous plates and made spatially uniform.