The present invention relates to an igniter assembly, including a blast tube provided with a supporting part formed in a cylindrical shape, and an aft-closure part having front and rear sides through which igniter combustion gas is emitted, an igniter disposed adjacent to the rear side of the aft-closure part and storing ignition pellet therein, and a blast tube stopper formed in a shape surrounding the supporting part, accommodating the igniter, and coupled to the rear side of the aft-closure part, wherein the aft-closure part includes a plurality of holes through which igniter combustion gas is emitted.