PROBLEM TO BE SOLVED: To prevent deterioration in an NOx removal catalyst due to sulfuric acid condensation in a denitration reaction chamber.SOLUTION: There is provided exhaust gas denitration equipment for a reciprocal engine which includes: an evaporation part which blows a reductant into an exhaust gas discharged from the reciprocal engine; a reaction part which brings the exhaust gas into which the reductant is blown into contact with a catalyst unit and sends the exhaust gas to a turbine side of a supercharger; and a bypass pipe which supplies the exhaust gas discharged from the reciprocal engine directly to the turbine side of the supercharger and can be opened and closed. The exhaust gas denitration equipment includes a purging air supply device which blows purging air into the reaction part and discharges an exhaust gas nearby the catalyst unit from the reaction part.