The invention relates to a core catcher and its manufacturing method, and an reactor container and its manufacturing method, to improve the efficiency for cooling the core debris, which is produced when the core in a reactor container melts and flows through the reactor container. The core debris, which is produced when the core in the reactor container melts and flows through the reactor container, is caught by a core catcher including a steel body (20), which is positioned below the reactor container and provided with cooling channels (21a) of a first stage and cooling channels (21b) of a second stage defined by cooling fins (31) extending radially in the reactor container. The number of the cooling channels (21b) of the second stage is larger than that of the cooling channels (21a) of the first stage. The cooling water is fed from a cooling water inlet (22) and distributed into the cooling channels (21a) of the first stage by a distributor (10). Between the cooling channels (21a, 21b) of the first and second stages, there is formed an intermediate header (24) for feeding the cooling channels (21b) of the second stage homogeneously, too, with the cooling water.