A compression molding method of an electronic component and a compression molding device therefore are provided. A horizontal nozzle (23) is firstly inserted in a horizontally extended state between an upper mold (6) and a lower mold (7). A liquid resin (4) is then discharged in a horizontal direction through a discharging port (29) in the horizontal nozzle (23) and thus is supplied into a cavity (10). Thereafter, the upper mold (6) and the lower mold (7) are closed. As a result, an electronic component (2) mounted on a substrate (1) is immersed in the liquid resin (4) in the cavity (10), and, thus, the electronic component (2) is resin sealed on the substrate (1) by compression molding.