The present disclosure relates to a soot blower including: a lance tube which includes one end that reciprocally moves in one direction on a surface of an inlet port of a flow path of the tubular heat exchanger; a drive unit which is connected to the lance tube and reciprocally moves and rotates the lance tube in the one direction; a first nozzle which is connected to the one end of the lance tube and discharges steam to the inlet port; and a second nozzle which is disposed adjacent to the first nozzle and connected to the one end of the lance tube and discharges solid particles to the inlet port, and the present disclosure relates to a method of cleaning a tubular heat exchanger by using the soot blower.