Provided is a hot air blower comprising a fuel tank for storing fuel, an air compression pump for sucking air and compressing the air, a pressure regulation valve installed at the air compression pump to reduce the pressure of the compressed air, a burner assembly for receiving the fuel from the fuel tank and the air from the air compression pump, and a combustion chamber for receiving the fuel from the burner assembly and combusting the fuel, wherein the pressure regulation valve includes a high pressure regulation valve and a low pressure regulation valve, and a valve opening/closing means is installed at the low pressure regulation valve.