①High-pressure gas (compressed gas, liquefied gas, special high-pressure gas), gas with higher pressure than atmospheric pressure (1 MPa or more) ⇒ Check the valve that should be closed for leaks (whether there is a valve open / close display, flow direction display)②Are the pressure gauge, densitometer, and detector showing normal values? ⇒ Check if it is broken or if it is used in a broken state (whether the regular inspection is checked correctly)③Are items that require regular calibration carried out as planned? ⇒ Is the management such as calibration performed as planned instead of newly calibrating (whether it is used without calibration)④Including oxygen deficiency due to N2 leakage, explosion due to organic solvent volatilization, etc. ⇒ Investigate not only high-pressure gas but also high risk such as explosion due to volatilization and dust, oxygen deficiency due to N2 leakage.⑤In addition, proper valve operation ⇒ Is the valve opening and closing quietly, is there an excessive force applied to the valve operation, and is a leak check performed after the valve is operated?