An apparatus for manufacturing a soft capsule containing a filling coated with a shell portion formed of a shell-sheet, having a sheet molding section forming a shell-sheet having an almost uniform thickness from a molten shell material, a capsule molding section feeding shell-sheets between a pair of die rolls and joining the shell sheets, and a filling supply section supplying a filling to the shell-sheets in time for joining the shell-sheets, in which the sheet molding section has a dryer equipped with a medium wavelength infrared heater; the shell-sheet is irradiated with a medium wavelength infrared ray from the heater to thereby obtain an almost uniform thickness, an appropriate viscosity, and moisture content; and the sheet of this state is fed to the capsule molding section.