An HC-adsorbent capable of adsorbing various kinds of hydrocarbon including lower and higher hydrocarbon, of which the adsorbable amount per unit volume is large, and which exhibits excellent durability at elevated temperatures. The HC-adsorbent is composed of a first zeolite of ZSM-5 of which the silica/alumina (SiO.sub.2 /Al.sub.2 O.sub.3) mole-ratio is 500 or more, and a second zeolite of Y-type zeolite of which the silica/alumina (SiO.sub.2 /Al.sub.2 O.sub.3) mole-ratio is 200 or more. The second zeolite mainly adsorbs higher hydrocarbon while the first zeolite mainly adsorbs lower hydrocarbon, thus enabling adsorption of many kinds of hydrocarbon.