Pressure medium oil and method for using said pressure medium oil

Provided are: a pressure medium oil including a group-14-element-containing organic compound selected from organic germanium compounds, organic tin compounds, and organic lead compounds; and a method for using pressure medium oil to apply pressure to a material via said pressure medium oil. This pressure medium oil does not solidify even under ultra-high pressures exceeding 3.7 GPa at room temperature (25 DEG C), has a low pour point, and does not tend to dissolve conductive paste. 提供包含选自有机锗化合物、有机锡化合物、和有机铅化合物的含有第14族元素的有机化合物的压力介质油、和介由该压力介质油而对物质施加压力的压力介质油的使用方法。该压力介质油具有在室温(25℃)下、超过3.7GPa的超高压下也不会固化、且倾点低、并且难以溶解导电糊剂的特性。