Fuel cell stack

A fuel cell stack comprising:

• a stacked body having a first end and a second end opposite to the first end in a stacking direction, comprising:
• power generation cells stacked in the stacking direction, each of the power generation cells comprising:
• an electrolyte film/electrode structure including an electrolyte film sandwiched between a first electrode and a second electrode in the stacking direction;
• and
• a separator stacked on the electrolyte film/electrode structure in the stacking direction and having an outer peripheral shape viewed in the stacking direction, the outer peripheral shape including a first short side, a second short side opposite to the first short side, and long sides opposite to each other and longer than the first and second short sides, the separator having a first knock pin insertion hole adjacent to the first side and a second knock pin insertion hole adjacent to the second side, each of the first knock pin insertion hole and the second knock pin insertion hole having a circular shape;
• a first knock pin inserted into the first knock pin insertion hole;
• a second knock pin inserted into the second knock pin insertion hole;
• a first insulating plate provided at the first end, having a third knock pin insertion hole provided to correspond to the first knock pin insertion hole, and having a fourth knock pin insertion hole provided to correspond to the second knock pin insertion hole;
• and
• a second insulating plate provided at the second end, having a fifth knock pin insertion hole provided to correspond to the first and third knock pin insertion holes, and having a sixth knock pin insertion hole provided to correspond to the second and fourth knock pin insertion holes, the first knock pin being inserted into the third and fifth knock pin insertion holes to be movable in the third and fifth knock pin insertion holes, the second knock pin being inserted into the fourth and sixth knock pin insertion holes to be movable in the fourth and sixth knock pin insertion holes.