To provide an exhaust system, reducing nitrogen oxide and particulate material at the same time by utilizing fuel decomposition catalyst and hydrocarbon selective catalyst reducing part in an exhaust device of a diesel automobile.

This exhaust device of a diesel automobile is equipped with: a fuel decomposition catalyst installed at the subsequent state of a turbo charger; a hydrocarbon selective catalyst reducing part installed behind the fuel decomposition catalyst; a catalyst coating type soot filtering device installed behind the hydrocarbon selective catalyst reducing part; and a fuel secondary injection system installed on a pipeline for exhaust gas between the turbo charger and the fuel decomposition catalyst.