An exhaust silencer device is provided. The device which is interposed in an exhaust passage in a vehicle to reduce exhaust noise comprises a sub-muffler (20) which is interposed in the exhaust passage and has an expansion chamber formed therein; an inlet pipe (30) which is airtightly inserted through an inlet opening (24) of the sub-muffler (20); and an outlet pipe (40) which is airtightly inserted through an outlet opening (26) of the sub-muffler (20), wherein the inlet pipe (30) and the outlet pipe (40) are formed with openings (small apertures (32, 42), non-joined portions) only in their upper half area and their lower half area is sealed without having the openings.