An exhaust purification device includes a PM filter and a differential pressure sensor for the PM filter, and calculates a first estimated amount PMf based on the operating state of the internal combustion engine and a second estimated amount PMc based on the differential pressure. The exhaust purification device performs an anomaly determination of the differential pressure sensor based on the state of the differential pressure sensor from stopping of the internal combustion engine to a startup thereof, and corrects the first estimated amount PMf based on the second estimated amount PMc when starting the internal combustion engine. The exhaust purification device calculates, as the PM deposition amount Pr, the larger value of the first and second estimated amounts, and starts a filter regeneration control of the PM filter when the PM deposition amount Pr is equal to or more than a first predetermined amount.