PURPOSE: To prevent the hollow part of a spacer fabric from being impregnated with paint by applying the specific paint in the state that both layers of the spacer fabric are closely connected with an intermediate web and then removing the restriction of the web.

CONSTITUTION: The intermediate web 7 is formed using meltable fibers 6 of hot-melt type based on copolyamide to connect the first and second layers 4, 5 of a velour fabric woven by an industrial yarn such as glass fiber by nailing or tufting. Then the velour fabric provided with the intermediate web is impregnated with a resin and the two layers 4, 5 are mutually stuck to obtain the spacer fabric of a three-layer sandwich structure so that both layers 4, 5 are separated from the web even after making into a prepreg from and the sticking state can be released by heating. When applying a liquid such as paint to the sheet metal connected to the spacer fabric, the application is carried out in a state where the layers 4, 5 are closely connected. Afterwards, the restriction by the web is removed to restore to the original spacer fabric having the hollow part between both layers 4, 5.