A gasification apparatus that is capable of appropriately controlling a differential pressure variation between the interior of a pressure vessel and the interior of a gasification furnace, and of simplifying a structure, by providing: a pressure vessel which forms a hollow shape; a gasification furnace which forms a hollow shape, and which is positioned inside the pressure vessel with a space section therebetween; a heat exchanger positioned at the upper section of the gasification furnace; a gas nozzle which supplies seal gas to the lower section of the space section; a char-receiving section provided above the heat exchanger in the space section; a pressure equalizer of which one end communicates with the interior of the gasification furnace, and the other end opens into the char-receiving section; and a gas flow channel which passes vertically through a side section of the char-receiving section.