A filter control device comprising a first estimation computing unit (100) for computing a first estimation data (XA) by means of a pressure difference across a filter in order to estimation-calculating a particulate deposition amount on the filter (32) and outputting it, and a second estimation computing unit (110) for outputting a second estimation data (XB) based on engine operation conditions, wherein estimation data whichever is higher in reliability in terms of an engine rotation speed at that time is selected out of the first and second estimation data (XA, XB) to determine whether to regenerate the filter or not and at the same time not to select the first estimation data (XA) having a possibly lower-reliability estimation value due to cracking of deposited particulates even when an engine rotation speed is high when the difference between the first and second estimation data (XA, XB) is larger than a specified value.