A head mounted display of which thickness may be reduced is disclosed. The head mounted display comprises a lens, and a display module accommodating unit for providing an image to the lens. The display module accommodating unit includes a display module for displaying an image, a first quarter wave (λ/4) plate arranged between the display module and the lens, delaying a phase of incident light as much as λ/4, a second quarter wave plate arranged between the first quarter wave plate and the lens, delaying a phase of incident light as much as λ/4, a reflective polarizing plate arranged between the second quarter wave plate and the lens, passing through first linear polarized light and reflecting second linear polarized light crossing the first linear polarized light, and a semi-transmissive plate arranged between the first quarter wave plate and the second quarter wave plate.