A head mounted apparatus mounted on a head of a user includes an apparatus body to be mounted on a front side of the head, a frame for supporting the apparatus body, the frame extending in a longitudinal direction at both sides of the head when the frame is mounted on the head, a front compressing portion provided on the frame or the apparatus body, and compressed against a frontal region of the head, first and second adjusters provided at both sides of the frame so that the first and second adjusters can move in the longitudinal direction relative to the frame, a back member that includes a back compressing portion compressed against an occipital region of the head, and is held by the first and second adjusters, and an interlock mechanism for enabling, as one of the first and second adjusters moves relative to the frame, the other of the first and second adjusters to move with the same moving amount relative to the frame in the same direction as the one.