Regeneration controller for exhaust purification apparatus of internal combustion engine

A regeneration controller for preventing particulate matter from increasing when an exhaust purification apparatus is inactivated. The regeneration controller includes an ECU for heating the exhaust purification apparatus and eliminating the particulate matter accumulated in the exhaust purification apparatus when an estimated accumulation amount is greater than a reference accumulation amount. The ECU obtains the estimated accumulation amount by estimating the amount of particulate matter accumulated in the exhaust purification apparatus. An exhaust temperature sensor detects the temperature of the exhaust purification apparatus. The ECU intermittently decreases the air-fuel ratio of exhaust to heat the exhaust purification apparatus and perform burn-up heating for burning the particulate matter. The ECU further prohibits burn-up heating when the temperature detected by an exhaust temperature sensor decreases to a catalyst inactivation level.