Abstract: An exhaust gas purifying apparatus employing a 3-way catalyst has either a Y-type zeolite or a mordenite as an adsorbent for adsorbing a harmful component in exhaust gas which is disposed at the upstream side of the catalytic converter so that, when the exhaust gas temeprature is not higher than a specific temperature, a harmful component is adsorbed by means of the adsorbent, whereas, when the exhaust gas temperature exceeds the specific temperature, the harmful component desorbed from the adsorbent is introduced into the catalytic converter. Further, an activated carbon trapper and a by-pass are provided in parallel at the upstream side of the adsorbent so that the flow paths of exhaust gas are selectively switched from one to the other in accordance with the level of the exhaust gas temperature.