Joining apparatus and heating system

A joining apparatus comprising:

• a stage including a support surface that is configured to support at least a first member among the first member and a second member included in a workpiece, and a first side surface that connects to the support surface and extends in a direction different from the support surface;
• a heater tool configured to heat the workpiece from a side of the second member in a state in which the second member is arranged on the first member supported by the support surface, thereby joining the first member and the second member;
• a vibration output device including a vibrator that is configured to ultrasonically vibrate and configured to cause the stage to ultrasonically vibrate during the joining;
• and
• a first preheating device configured to heat the stage in noncontact before the joining, thereby preheating at least the first member of the workpiece,
• wherein the first preheating device includes:
• a light source that faces the first side surface of the stage and is configured to emit heating light for heating the stage;
• and
• a reflecting surface that has a hood shape and covers the light source from a side opposite to the first side surface, the reflecting surface being configured to reflect, toward the first side surface, light that has been reflected by the first side surface among the heating light.