A lighting device for turning on a solid state light-emitting device at brightness according to a dimming signal, the lighting device comprising: a lighting circuit to which a direct-current voltage is inputted, including a coil for chopping the inputted DC voltage and a diode for regenerating energy stored in the coil; a drive circuit including an input terminal to which a pulse width modulation signal is inputted, and a switching element for turning on and off a current flowing through the coil by repeatedly turning on and off in a burst period which is a period corresponding to a duty ratio indicated by the PWM signal inputted to the input terminal; a dimmer control circuit for generating a PWM signal which has a duty ratio corresponding to the dimming signal; and a low pass filter for smoothing the PWM signal generated by the dimmer control circuit, and outputting the smoothed PWM signal to the input terminal of the drive circuit, wherein the PWM signal generated by the dimmer control circuit has a pulse height including a first threshold and a second threshold greater than the first threshold, the smoothed PWM signal includes a first time period in which the pulse height is greater than the first threshold and less than the second threshold, and a second time period in which the pulse height is greater than or equal to the second threshold, and the drive circuit increases on-time as the pulse height of the smoothed PWM signal increases in the first time period, and makes the on-time constant in the second time period, the on-time being a period for which the switching element is on when the switching element turns on and off once in the burst period. a lighting circuit to which a direct-current voltage is inputted, including a coil for chopping the inputted DC voltage and a diode for regenerating energy stored in the coil; a drive circuit including an input terminal to which a pulse width modulation signal is inputted, and a switching element for turning on and off a current flowing through the coil by repeatedly turning on and off in a burst period which is a period corresponding to a duty ratio indicated by the PWM signal inputted to the input terminal; a dimmer control circuit for generating a PWM signal which has a duty ratio corresponding to the dimming signal; and a low pass filter for smoothing the PWM signal generated by the dimmer control circuit, and outputting the smoothed PWM signal to the input terminal of the drive circuit, wherein the PWM signal generated by the dimmer control circuit has a pulse height including a first threshold and a second threshold greater than the first threshold, the smoothed PWM signal includes a first time period in which the pulse height is greater than the first threshold and less than the second threshold, and a second time period in which the pulse height is greater than or equal to the second threshold, and the drive circuit increases on-time as the pulse height of the smoothed PWM signal increases in the first time period, and makes the on-time constant in the second time period, the on-time being a period for which the switching element is on when the switching element turns on and off once in the burst period.