In a case where DPF regeneration is restarted after an engine is automatically restarted from interruption of the DPF regeneration, DPF regeneration control is corrected so as to suppress temperature rise due to the DPF regeneration in consideration of an increment in oxygen concentration in exhaust gas which is caused due to the interruption of the DPF regeneration. Specifically, restart of the DPF regeneration is prohibited during a predetermined prohibition time ΔT1 from a time t1 at which the engine is automatically restarted, and a post injection amount of fuel is corrected to the side of reduction.