Joining device and joining method

A joining device that joins a plurality of joining target members being stacked, the joining device comprising:

• a pair of pressing members disposed to face each other to sandwich the plurality of joining target members from both sides in a stacking direction of the plurality of joining target members and configured to press the plurality of joining target members;
• and
• a plurality of power supply members disposed on one or both sides in the stacking direction of the plurality of joining target members to sandwich a pressing target portion of the plurality of joining target members by the pressing members, the plurality of power supply members being configured to come into contact with and supply power to the joining target members, wherein
• the power supply members are provided at positions not overlapping the pressing members in the stacking direction of the plurality of joining target members, and
• the pressing members press the plurality of joining target members while the power supply members supply power to the plurality of joining target members, thereby generating resistance heat in the pressing target portion and joining the plurality of joining target members.