To provide a manufacturing method for efficiently manufacturing a sintering powder with less impurities, to which nitrogen is instantaneously added as an alloy element, without performing nitrogen treatment for a long time even when raw material powder of a low-cost alloy composition containing no nitrogen is used, and also obtaining a powder sintered body with high strength and excellent corrosion resistance.

The manufacturing method of the powder sintering body containing nitrogen includes a step for preparing the raw material powder of predetermined mass, a step for forming plasma flame by a plasma operation gas and high frequency energy generated by a high frequency induction coil, and adjusting nitrogen concentration of a space where the plasma flame exists to 5 vol.% or more, a step for melting and coagulating the raw material powder by throwing it into the plasma flame to obtain the sintering powder containing 0.1 mass% or more of nitrogen, and a step for sintering the sintering powder.