There is provided a thermal fixing unit that fixes a toner image on a printing medium, the fixing unit including a heat member, a pressure pad, a movable supporting assembly, and an urging member. The heat member is in contact with the printing medium, being positionally fixed and defining an axis. The pressure pad is disposed in opposition to the heat member for nipping the printing medium in cooperation with the heat member. The supporting assembly pivotably movably supports the pressure pad. The urging member biases the supporting assembly to urge the pressure pad toward the heat member for providing pressure contact between the heat member and the pressure pad.