A temperature sensor (10) includes: a temperature-sensing portion for measuring a temperature of an object (50) by contacting the object; and a supporting portion for supporting the temperature-sensing portion from a side opposite to a contact surface, the supporting portion having a space at a portion partially corresponding to the temperature-sensing portion. A temperature controller includes: a temperature control device; the temperature sensor (10) for measuring the temperature by contacting the object (50); and a controller for controlling the temperature control device. The controller includes: a mounting-state judging means for judging a mounting-state of the object (50); a switching means for switching a control gain and a target temperature of the temperature control device based on the judging result; and a control-command generating means for generating a control command based on the control gain, the target temperature and a measurement value of the temperature sensor (10).