EXHAUST PURIFICATION SYSTEM

The present invention relates to an exhaust purification system and detects an amount of PM accumulated in a DPF with high precision. The exhaust purification system includes: a DOC (21) provided on an exhaust passage (12) of an engine (10); a DPF (22) provided on the exhaust passage (12) at a position downstream of the DOC (21) to collect the PM contained in exhaust gas; electrodes (27) that detect a capacitance of the DOC (21); a PM accumulation estimating unit (51) that estimates an amount of PM accumulated in the DPF (22) on the basis of the capacitance received from the electrodes (27); and a forced regeneration control unit (53) that injects fuels into the DOC (21) and performs forced regeneration that burns and removes at least the PM accumulated in the DPF (22) when the accumulated PM amount that is received from the PM accumulation estimating unit (51) surpasses a predetermined amount.