An extrusion die for extrusion molding of a honeycomb structure has back holes for introducing a raw material to be molded and slits for extruding the raw material. The extrusion die comprises an inside section, an outer peripheral section, and an outermost peripheral section; the width of the slit 14 disposed in the outer peripheral section is wider than the width of the slit disposed in the inside section; and when the surface roughness (Ra) of the slits in the inside section and the outer peripheral section is 0.1 .mu.m or smaller, or when the surface roughness (Ra) of the slits in the inside section and the outer peripheral section exceeds 0.1 .mu.m, the relationship between the surface roughness a of slit in the inside section and the surface roughness b of slit in the outer peripheral section satisfies the condition that 0.1