A method of press forming includes: forming a trench-shaped portion into a product shape with a die and a punch until reaching a first bottom dead center, and forms at least one of: a flange portion subject to shrink flange deformation such that a linear length of the flange portion subject to the shrink flange deformation in a longitudinal direction is shorter than a linear length of a flange portion in the product shape; and a flange portion subject to stretch flange deformation such that a linear length of the flange portion subject to the stretch flange deformation in the longitudinal direction is longer than the linear length of the flange portion in the product shape; and forming the formed flange portion into the product shape with the die and a flange forming die until reaching a second bottom dead center.