A safety lighter includes a lighter body comprising a casing defining a liquefied gas chamber for containing a predetermined volume of liquefied gas therein, a supporting frame having an outer sealing surface engaged with an inner surface of the casing, a gas emitting nozzle mounted on the supporting frame to communicate with the liquefied gas chamber, and an ignition device supported by the supporting frame for ignition. A sealing arrangement includes upper and lower sealing rims spacedly and integrally provided along an opening portion of the inner surface of the casing in a step-shouldering manner wherein the upper and lower sealing rims are sealed with the outer sealing surface of the supporting frame to form two sealing lines along the upper and lower sealing rims respectively to sealedly mount the supporting frame on the lighter body for sealedly retaining the liquefied gas within the liquefied gas chamber.