A particulate matter sensor for exhaust gas comprising: a filter member (31, 61) having a plurality of cells which are defined by a porous partition wall; at least a pair of electrode members (32, 33, 62, 63) which are disposed to face each other with a cell among the plurality of cells sandwiched therebetween to form a condenser; a heater member (34, 64) configured to heat the cells to burn and remove particulate matter accumulated in the cells; an electrostatic capacity detection circuit configured to detect an electrostatic capacity between the pair of electrode members; and an estimation unit configured to estimate an amount of the particulate matter contained in the exhaust gas based on the electrostatic capacity between the pair of electrode members detected by the electrostatic capacity detection circuit, wherein the filter member is a filter layer in which the plurality of cells are disposed in parallel in one direction, wherein the pair of electrode members are first and second planar electrode plates which are disposed to face each other with the filter layer sandwiched therebetween, and characterized in that the heater member is one of: a planar heater substrate which is configured to be energized to be heated, and is interposed either between the first electrode plate and the filter layer or between the second electrode plate and the filter layer along a flow path, and a heating wire which is inserted into the cell and which is configured to be energized to be heated. a filter member (31, 61) having a plurality of cells which are defined by a porous partition wall; at least a pair of electrode members (32, 33, 62, 63) which are disposed to face each other with a cell among the plurality of cells sandwiched therebetween to form a condenser; a heater member (34, 64) configured to heat the cells to burn and remove particulate matter accumulated in the cells; an electrostatic capacity detection circuit configured to detect an electrostatic capacity between the pair of electrode members; and an estimation unit configured to estimate an amount of the particulate matter contained in the exhaust gas based on the electrostatic capacity between the pair of electrode members detected by the electrostatic capacity detection circuit, wherein the filter member is a filter layer in which the plurality of cells are disposed in parallel in one direction, wherein the pair of electrode members are first and second planar electrode plates which are disposed to face each other with the filter layer sandwiched therebetween, and characterized in that the heater member is one of: a planar heater substrate which is configured to be energized to be heated, and is interposed either between the first electrode plate and the filter layer or between the second electrode plate and the filter layer along a flow path, and a heating wire which is inserted into the cell and which is configured to be energized to be heated. a planar heater substrate which is configured to be energized to be heated, and is interposed either between the first electrode plate and the filter layer or between the second electrode plate and the filter layer along a flow path, and a heating wire which is inserted into the cell and which is configured to be energized to be heated.