To provide a fire extinguisher having a resin-made fire extinguishing agent storage container which is light in weight and has extremely high strength.

For a fire extinguisher 100, a fire extinguishing agent storage container 10 includes a mouth portion to be an opening, a shoulder portion, a cylindrical body portion, and a bottom portion, and is formed with a resin with no joint. In addition, the body portion in the fire extinguishing agent storage container 10 has a thickness from 1 mm to 5 mm, and the crystallinity of the resin is from 13% to 30% at the sites other than the mouth portion and the bottom portion, and when the pressure of 2.6 MPa is applied to the fire extinguishing agent storage container 10, the fire extinguishing agent storage container 10 is not cracked or broken. Accordingly, the fire extinguisher 100 is made light in weight and does not rust. Further, the fire extinguisher 100 has high strength or high pressure resistance.