Abstract: Power supplying unit to be used for supplying power to such a load as the motor for driving a submerged pump that scoops liquid out of a tank storing low temperature liquid like LNG and so forth. The power supplying unit has a ceramic sleeve fixed to the flange, a penetrating conductor inserted into this ceramic sleeve, and the ceramic sleeve and the penetrating conductor are coupled air-tightly to each other inside the flange (inside the tank) sealed outside the flange with a bellows of semi-mountain construction in cross section. The bellows has an elasticity and is mounted, when the ceramic sleeve and the penetrating conductor are linearly expanded at the maximum temperature during practical or normal use, or at the temperature slightly higher than the said level. The bellows is mounted between the ceramic sleeve and the penetrating conductor in a state where it is displaced to its maximum length due to its self elasticity.