To provide a reciprocating end combustion gas generator that overcomes such problems that the conventional apparatus using a gas generating agent of end combustion type having a cylindrical shape has been limitated in the degree of freedom of design due to the increase of length in the longitudinal axis direction of the gas generating agent in proportion to the combustion time.

In the reciprocating end combustion gas generator A1, the gas generating agent is charged in a combustor 4 in multi-layer state through a restrictor 9 and the gas generating 10 in each layer is placed in continuation so that the end combustion proceeds sequently in each layer. Thus, the generator A1 is improved in the degree of freedom of design extremely by realizing a large elongation of the combustion time without increasing the whole length of the combustor 4.