To provide a device for safely executing high pressure liquid phase continuous reaction using a microwave capable of accelerating chemical reaction a heating source.

The multilayer pressure-resistant structure type reactor is constituted by attaching a pressure-resistance shell capable of safely collecting and recovering a high temperature and high pressure reaction material to the outer periphery of the reaction tube when the reaction material is projected by the pressure-resistant reaction tube being broken constituted of a microwave transmitting material such as glass, a plastic, and a ceramic due to an unexpected event during reaction. In this case, it is possible to form the shell with one layer but the safety is further enhanced by forming the shell with two layers of an inner shell and an outer shell. In the case of two layer shell, a pressure inside of the inner shell can be held and controlled in the same level as the pressure in the reaction tube. Thereby, in this case it is possible to suppress the generation of the unexpected event such as the breakage of the reaction tube.