A manufacturing method of a separator for a fuel cell, including: preparing a first die including: a first convex surface and a first concave surface; and a first side surface connected between the first convex surface and the first concave surface; preparing a second die including: a second concave surface and a second convex surface respectively facing the first convex surface and the first concave surface; and a second side surface facing the first side surface and connected between the second concave surface and the second convex surface; preparing a metal plate having a flat plate shape, and two electro-conductive resin sheets; and forming a flow channel in the metal plate and the two electro-conductive resin sheets by hot pressing with the first and second dies.