A regeneration controller that prevents overheating when performing burn-up heating for completely burning particulate matter by intermittent fuel addition to an exhaust system or intermittent increase of fuel addition to the exhaust system. The regeneration controller includes first and second exhaust temperature sensors (44, 46), each detecting the exhaust temperature at a location downstream from the exhaust purification apparatus. An ECU (70) determines the timing for stopping fuel addition to the exhaust system or increase of fuel addition to the exhaust system based on the elapsed time of fuel addition to the exhaust system or increase of fuel addition to the exhaust system.