An engine system comprising: a diesel engine; an exhaust passage connected to the engine; a DPM filter provided on the exhaust passage, which traps diesel particulate matter contained in an exhaust gas of the engine; a temperature adjusting device coupled to the engine, the temperature adjusting device adjusting an exhaust gas temperature of the engine and a controller coupled to the temperature adjusting device, the controller functioning to: determine a filter differential pressure, which is a difference between an inlet pressure and an outlet pressure of the DPM filter; estimate the trapped DPM amount in the DPM filter on the basis of the filter differential pressure using a trapped DPM amount calculation processes; and control the temperature adjusting device to raise the exhaust gas temperature when the estimated trapped DPM amount becomes greater than a predetermined value to regenerate the DPM filter by burning the DPM trapped in the DPM filter, characterized in that said controller is functioning to: switch between a first trapped DPM amount calculation process for estimating the trapped DPM amount after complete regeneration, in which all of the DPM trapped in the DPM filter is burned, and a second trapped DPM amount calculation process for estimating the trapped DPM amount when a part of the DPM trapped in the DPM filter has been burned away, in accordance with a regeneration condition of the DPM filter. a diesel engine; an exhaust passage connected to the engine; a DPM filter provided on the exhaust passage, which traps diesel particulate matter contained in an exhaust gas of the engine; a temperature adjusting device coupled to the engine, the temperature adjusting device adjusting an exhaust gas temperature of the engine and a controller coupled to the temperature adjusting device, the controller functioning to: determine a filter differential pressure, which is a difference between an inlet pressure and an outlet pressure of the DPM filter; estimate the trapped DPM amount in the DPM filter on the basis of the filter differential pressure using a trapped DPM amount calculation processes; and control the temperature adjusting device to raise the exhaust gas temperature when the estimated trapped DPM amount becomes greater than a predetermined value to regenerate the DPM filter by burning the DPM trapped in the DPM filter, characterized in that said controller is functioning to: switch between a first trapped DPM amount calculation process for estimating the trapped DPM amount after complete regeneration, in which all of the DPM trapped in the DPM filter is burned, and a second trapped DPM amount calculation process for estimating the trapped DPM amount when a part of the DPM trapped in the DPM filter has been burned away, in accordance with a regeneration condition of the DPM filter. determine a filter differential pressure, which is a difference between an inlet pressure and an outlet pressure of the DPM filter; estimate the trapped DPM amount in the DPM filter on the basis of the filter differential pressure using a trapped DPM amount calculation processes; and control the temperature adjusting device to raise the exhaust gas temperature when the estimated trapped DPM amount becomes greater than a predetermined value to regenerate the DPM filter by burning the DPM trapped in the DPM filter, characterized in that said controller is functioning to: switch between a first trapped DPM amount calculation process for estimating the trapped DPM amount after complete regeneration, in which all of the DPM trapped in the DPM filter is burned, and a second trapped DPM amount calculation process for estimating the trapped DPM amount when a part of the DPM trapped in the DPM filter has been burned away, in accordance with a regeneration condition of the DPM filter. switch between a first trapped DPM amount calculation process for estimating the trapped DPM amount after complete regeneration, in which all of the DPM trapped in the DPM filter is burned, and a second trapped DPM amount calculation process for estimating the trapped DPM amount when a part of the DPM trapped in the DPM filter has been burned away, in accordance with a regeneration condition of the DPM filter.