Exhaust gas purifying device for internal combustion engine

An exhaust gas purifying device for an internal combustion engine, comprising:

• an electrically heated catalyst which has a catalyst carrier supporting a catalyst and a carrier retention member which is provided on an outer periphery of the catalyst carrier, which retains the catalyst carrier, and which has an electrical insulation property;
• a cooler which cools the carrier retention member;
• and
• a controller programmed to control the cooler to cool the carrier retention member so that the temperature of the carrier retention member is lowered to ensure an insulation property of the carrier retention member, when a temperature of the catalyst is lower than a first predetermined temperature and a temperature of the carrier retention member is equal to or higher than a second predetermined temperature;
• the controller is programmed to control the cooler such that the cooler does not cool the carrier retention member when the temperature of the catalyst is equal to or higher than the first predetermined temperature;
• and
• the controller is programmed to control the cooler such that the cooler does not cool the carrier retention member when the temperature of the carrier retention member is lower than the second predetermined temperature.