The present invention relates to an HMD, the HMD comprising: a display barrel provided on the body and having a display arranged on one side thereof; a lens barrel for adjusting a focal point by movement relative to the display barrel; and a sealing portion provided between the display barrel and the lens barrel to maintain the airtightness of a space between the display barrel and the lens barrel, wherein the sealing portion has at least one end coupled to the outer circumferential surface of the display barrel, and is expanded and contracted according to the movement of the display barrel.