An exhaust gas control apparatus includes an oxidation catalyst, a compact oxidation catalyst having a smaller cross section than that of an engine exhaust passage, a fuel supply valve, a glow plug, and an electronic control unit. The control modes for the exhaust gas control apparatus include a first control mode where the fuel is supplied from the fuel supply valve, heated by the glow plug, and ignited, a second control mode where the fuel is supplied from the fuel supply valve, and heated by the glow plug but is not ignited, and a third control mode where the fuel is supplied from the fuel supply valve and the glow plug does not provide heating. The electronic control unit selects the first or third control mode in the operation region where ignition is possible, and selects the second or third control mode in the operation region where ignition is not possible.