To provide a NOx adsorbing device which effectively adsorbs NOx in the range of high temperature to low temperature and also reduces a discharge amount of NOx from a NOx reduction catalyst arranged in the downstream side of the exhaust gas.

A first NOx adsorbing material 20 having a peak temperature of 200C or below at which the adsorbed-NOx releasing amount is the maximum is arranged in the upstream side of the exhaust gas, and a second NOx adsorbing material 21 having a peak temperature higher than 200C at which the adsorbed-NOx releasing amount is the maximum is arranged in the downstream side of the exhaust gas of the first NOx adsorbing material 20. NOx is adsorbed on the first NOx adsorbing material 20 in the lower temperature area, and NOx desorbed from the first NOx adsorbing material 20 in the higher temperature area is again adsorbed on the second NOx adsorbing material 21.