A regeneration device for a filter (13) which traps particulate matter in an exhaust gas of an engine (1) is disclosed. The regeneration device has a sensor (25) which detects an engine running point containing an engine load and a controller (22) storing a map which defines a low load region (A) relating to engine running points. The controller (22) determines whether or not the detected engine running point is in the low load region referring to the map, when the deposition amount of particulate matter is more than a first reference amount (PMn). Further, the controller (22) immediately start a first filter regeneration control by raising a temperature of the exhaust gas, when the detected engine running point is not in the low load region, and start a second filter regeneration control by raising the temperature of the exhaust gas after the deposition amount of particulate matter exceeds a second reference amount (PMe), when the detected engine running point is in the low load region.