A non-see-through HMD (10, 20) comprising: a main body part configured to block an external situation from a field of view of a user when the user wears the non-see-through HMD (10, 20); at least one inner display screen (313a, 313b) mounted at an inner side of the main body part opposite to the user when the user wears the non-see-through HMD; an outside information detection unit including at least an image-capturing device and an infrared sensor device and a distance sensor device, wherein the outside information detection unit is configured to capture outside information including an external image indicating an external situation, the outside information further including distance information representing a distance to an object in an outside environment, the outside information further including a direction of the object; the non-see-through HMD (10, 20) being characterized in that the non-see-through HMD (10, 20) further comprises a control unit configured to acquire a content image, determine, based on the distance to the object, a degree of necessity that the user of the non-see-through HMD be notified of the distance to the object; display, on the at least one inner display screen (313a, 313b), the content image; superimpose, on the at least one inner display screen (313a, 313b), a circular pattern over the content image, the circular pattern indicating the direction of the object and the distance to the object with respect to the user of the non-see-through HMD; and control, based on the degree of necessity, the at least one inner display screen (313a, 313b) to increase a size of the circular pattern, which is superimposed over the content image, as the distance to the object decreases. a main body part configured to block an external situation from a field of view of a user when the user wears the non-see-through HMD (10, 20); at least one inner display screen (313a, 313b) mounted at an inner side of the main body part opposite to the user when the user wears the non-see-through HMD; an outside information detection unit including at least an image-capturing device and an infrared sensor device and a distance sensor device, wherein the outside information detection unit is configured to capture outside information including an external image indicating an external situation, the outside information further including distance information representing a distance to an object in an outside environment, the outside information further including a direction of the object; the non-see-through HMD (10, 20) being characterized in that the non-see-through HMD (10, 20) further comprises a control unit configured to acquire a content image, determine, based on the distance to the object, a degree of necessity that the user of the non-see-through HMD be notified of the distance to the object; display, on the at least one inner display screen (313a, 313b), the content image; superimpose, on the at least one inner display screen (313a, 313b), a circular pattern over the content image, the circular pattern indicating the direction of the object and the distance to the object with respect to the user of the non-see-through HMD; and control, based on the degree of necessity, the at least one inner display screen (313a, 313b) to increase a size of the circular pattern, which is superimposed over the content image, as the distance to the object decreases. acquire a content image, determine, based on the distance to the object, a degree of necessity that the user of the non-see-through HMD be notified of the distance to the object; display, on the at least one inner display screen (313a, 313b), the content image; superimpose, on the at least one inner display screen (313a, 313b), a circular pattern over the content image, the circular pattern indicating the direction of the object and the distance to the object with respect to the user of the non-see-through HMD; and control, based on the degree of necessity, the at least one inner display screen (313a, 313b) to increase a size of the circular pattern, which is superimposed over the content image, as the distance to the object decreases.