A vehicle headlight comprising: a projection lens disposed on an optical axis extending in a front-to-rear direction of a vehicle body; a light-emitting device including a semiconductor laser element configured to emit a laser beam and a light-transmitting member configured to absorb and convert the wavelength of at least part of the laser beam from the semiconductor laser element; a first reflection surface configured to reflect the light from the light-emitting device so as to transmit and project forward the resulting light through the projection lens; a light detection unit configured to detect a light beam of a specific color, and a control unit configured to control the semiconductor laser element in accordance with a detection result provided by the light detection unit so that the semiconductor laser element does not emit the laser beam; wherein the light of a specific color is a light beam that is wavelength-converted by the light-transmitting member, and wherein the control unit is configured to control the semiconductor laser element so as to stop emitting a laser beam when the semiconductor laser element is emitting the laser beam and when the light detection unit does not detect light that has been wavelength-converted by the light-transmitting member, characterized by the light detection unit being disposed between the projection lens and the light-emitting device and below the optical axis, and a second reflection surface having a first focus (F1 28C) at or near the light-transmitting member and configured to reflect the light beam from the light-emitting device toward the light detection unit, the second reflection surface being integrally provided to the front end of the first reflection surface and being disposed ahead of the front end of the first reflection surface. a projection lens disposed on an optical axis extending in a front-to-rear direction of a vehicle body; a light-emitting device including a semiconductor laser element configured to emit a laser beam and a light-transmitting member configured to absorb and convert the wavelength of at least part of the laser beam from the semiconductor laser element; a first reflection surface configured to reflect the light from the light-emitting device so as to transmit and project forward the resulting light through the projection lens; a light detection unit configured to detect a light beam of a specific color, and a control unit configured to control the semiconductor laser element in accordance with a detection result provided by the light detection unit so that the semiconductor laser element does not emit the laser beam; wherein the light of a specific color is a light beam that is wavelength-converted by the light-transmitting member, and wherein the control unit is configured to control the semiconductor laser element so as to stop emitting a laser beam when the semiconductor laser element is emitting the laser beam and when the light detection unit does not detect light that has been wavelength-converted by the light-transmitting member, characterized by the light detection unit being disposed between the projection lens and the light-emitting device and below the optical axis, and a second reflection surface having a first focus (F1 28C) at or near the light-transmitting member and configured to reflect the light beam from the light-emitting device toward the light detection unit, the second reflection surface being integrally provided to the front end of the first reflection surface and being disposed ahead of the front end of the first reflection surface.