To provide a pressurizing type powder fire extinguisher which can secure the passage of a powder extinguishing agent through an extinguishing agent discharge pipe 9 even when a seal plate mounting device 15 is mounted at the lower end of the extinguishing agent discharge pipe 9 leaving no distance from an inner bottom surface 1a of a body container 1.

A recessed cut part 26 for securing the passage of the powder extinguishing agent is provided at the lower end 16a of a surrounding wall 16 of the seal plate mounting device 15 mounted at the lower end of the extinguishing agent discharge pipe 9.