To prevent the generation of belt-shaped line patterns in a building interior/exterior aluminum extrusion molding material, and to obtain a material having good uniformity on the surface of outward appearance without making surface treatment for reducing the number of belt-shaped line patterns.

A building interior/exterior extrusion molding material is so constituted that a large number of fine narrow grooves continued in the extruding direction of the extrusion molding material and arranged at right angles to the extruding direction are formed in a part for requiring at least the uniformaty on the surface of outward appearance. Each of the fine narrow grooves is 0.005-0.1mm in depth, 0.05-1.0mm in width, and an interval between the fine narrow grooves adjacent to each other is at most 1mm.