A head-up display for a vehicle, according to one embodiment of the present invention, may comprise: an image source which emits a linearly-polarized light having a first direction; a prism which refracts one portion of the linearly-polarized light emitted from the image source; an electric polarization conversion element which, when turned off, transmits another portion of the linearly-polarized light emitted from the image source, and when turned on, half-wavelength-converts the another portion of the linearly-polarized light emitted from the image source into a linearly-polarized light having a second direction orthogonal to the first direction; a first reflection mirror which reflects light to a windshield of a vehicle; a polarization reflection mirror which is disposed so as to be spaced apart from the first reflection mirror, reflects the linearly-polarized light having the first direction, and transmits the linearly-polarized light having the second direction; and a second reflection mirror which is disposed so as to be spaced apart from the polarization reflection mirror, and reflects the light transmitted through the polarization reflection mirror to the polarization reflection mirror.