A CO2 trapping device mounted in a hybrid vehicle, provided with a branch passage branched from an exhaust passage, a CO2 trapping part provided at the branch passage and trapping CO2 in inflowing exhaust gas, a cooling part using electric power of the battery to cool the CO2 trapping part, a flow controlling part controlling an amount of flow of the exhaust gas flowing into the branch passage, and a CO2 trapping control part controlling the cooling part and the flow controlling part, the CO2 trapping control part controlling the flow controlling part so as to make the cooling part stop cooling and to shut off the flow of the exhaust gas to the CO2 trapping part when a charging rate of the battery becomes a predetermined SOC threshold value or less.