Abstract: The invention provides a soft starter device for lamps. The soft starter device includes a rectifying circuit for converting an AC voltage into a DC voltage which serves as a triggering signal; a high frequency voltage generating circuit for generating a high frequency voltage by an oscillation between two transistors; a high frequency output transformer electrically connected to the high frequency voltage generating circuit and having a primary coil and a secondary coil; a first capacitor for providing a momently high voltage to a lamp tube by generating a resonance together with the high frequency output transformer; and a control circuit having a charging circuit and a switch for grounding the secondary coil connected thereto or allowing the secondary coil to function normally. At the initial time of power supplying, the switch is turned on to ground the secondary coil, causing the primary coil being not able to function, such that only a current flows into the lamp tube to preheat the filaments thereof.