a strobe device including a light - emitting tube , a main capacitor which accumulates energy and which supplies the energy to the light - emitting tube , a transformer circuit which includes primary and secondary coils in order to accumulate the energy of a power supply in the main capacitor , wherein the primary coil is connected to the power supply and the secondary coil is connected to the main capacitor , a control circuit which controls a current flowing from the power supply to the primary coil , wherein a current starts to flow through the secondary coil after the control circuit stops a current flowing through the primary coil , and a determination circuit which determines that a malfunction has occurred in accordance with a current flowing through the secondary coil .