A modular structure of a fuel cell is provided, which includes a membrane electrode assembly (MEA), at least one first electrode plate, at least one second electrode plate, at least one first fixing element and at least one second fixing element. The first electrode plate is disposed at one side of the MEA and has at least one first through hole. The second electrode plate is disposed at the other side of the MEA and has at least one second through hole corresponding to the first through hole. The first fixing element and the second fixing element correspond to each other, and are joined to each other through the first through hole and the second through hole to fix the first electrode plate and the second electrode plate for the first electrode plate, the MEA and the second electrode plate to form a single cell module.