To provide a sheet member which is excellent in assembly performance enabling the sheet member to be easily mounted on a predetermined position, and to provide an exhaust gas purifying device having the same.

The sheet member contains inorganic fiber and comprises a first surface and a second surface which are mutually opposite and substantially perpendicular to the thickness direction of the sheet member; at least the first surface is provided with a concave part and a convex part, and the maximum difference (the maximum concave and convex difference) h between the concave part and the convex part of the first surface is within a range of 0.4 mm to 9 mm, and the concave part and the convex part are obtained by a heating, compressing and drying process. When the first surface of the sheet member is disposed in contact with other members, as the concave and convex parts are formed on the first surface, the contact area of the sheet member and other members is decreased, thus reducing the friction force generated when the sheet member is horizontally moved with respect to other members.