[Object] To provide a press-molding apparatus capable of appropriately thickening a vertical wall portion while preventing the occurrence of buckling.[Solution] Provided is a press-molding apparatus configured to mold a press-molded product by performing press working on a work, the press-molding apparatus including: a support member that supports the work with a first thickness having a hat-shaped cross-section or a U-shaped cross-section; a punch member that moves relative to the support member to execute press working so as to reduce a height of a vertical wall portion of the work and thicken the vertical wall portion to a second thickness; and a pad member that faces the support member with the vertical wall portion to be thickened placed therebetween, the pad member being biased by a biasing member and having its distance to the support member kept equal to or smaller than the second thickness during the press working.