Illumination apparatus

An illumination apparatus including: a power supply circuit which outputs a DC power obtained by rectifying an AC voltage and stepping up the rectified voltage; a light source unit having semiconductor light emitting elements turned on by the DC power; and a housing formed of a conductive material that is grounded through a ground path and on which the power supply circuit and the light source unit are mounted. When one of power feed lines is cut off, the light emitting elements are supplied with an AC power from an AC power source through the ground path and a stray capacitance formed between the light source unit and the housing such that a forward voltage of the light emitting elements generates a light emission level hardly recognizable by a human eye.