An eyewear comprising: an input unit that receives an input from a user; a control module that is accommodated in a temple so as to perform electric control in response to the input from the input unit; a power supply unit that has a first electrical connection terminal arrangement having two electrical terminals and a housing unit for accommodating a battery; an accommodating unit that is located in a rear end portion of the temple, and that is open on an inner surface and a rear surface continuous with the inner surface of the temple so as to detachably accommodate the power supply unit; and a second electrical connection terminal arrangement that is accommodated in the temple, and that is electrically connected to the first electrical connection terminal arrangement of the power supply unit accommodated in the accommodating unit so as to supply power from the power supply unit to the control module, wherein the accommodating unit has a protruding portion which is elastically deformed so as to be fitted to the power supply unit, wherein the housing unit is provided with a narrow portion to which the protruding portion is fitted when the power supply unit is mounted on the accommodating unit, wherein, in a state where the power supply unit is mounted on the accommodating unit, a side surface of the housing unit is covered by the protruding portion, a rear surface and an upper surface adjacent to the rear surface of the housing unit of the power supply unit in a direction in which the power supply unit is inserted into the accommodating unit are respectively exposed from the rear surface and the inner surface of the temple so as to form a portion of a surface of the temple, and the power supply unit is not exposed on an outer surface of the temple which is located on a side opposite to the inner surface of the temple, wherein the electrical connection terminals are disposed at a predetermined interval, and wherein a projection portion having a predetermined height is disposed between the electrical connection terminals; wherein the projection portion extends from a front end of the power supply unit to a front portion of the side surface of the housing unit, and is brought into contact with or fixed to the front portion. an input unit that receives an input from a user; a control module that is accommodated in a temple so as to perform electric control in response to the input from the input unit; a power supply unit that has a first electrical connection terminal arrangement having two electrical terminals and a housing unit for accommodating a battery; an accommodating unit that is located in a rear end portion of the temple, and that is open on an inner surface and a rear surface continuous with the inner surface of the temple so as to detachably accommodate the power supply unit; and a second electrical connection terminal arrangement that is accommodated in the temple, and that is electrically connected to the first electrical connection terminal arrangement of the power supply unit accommodated in the accommodating unit so as to supply power from the power supply unit to the control module, wherein the accommodating unit has a protruding portion which is elastically deformed so as to be fitted to the power supply unit, wherein the housing unit is provided with a narrow portion to which the protruding portion is fitted when the power supply unit is mounted on the accommodating unit, wherein, in a state where the power supply unit is mounted on the accommodating unit, a side surface of the housing unit is covered by the protruding portion, a rear surface and an upper surface adjacent to the rear surface of the housing unit of the power supply unit in a direction in which the power supply unit is inserted into the accommodating unit are respectively exposed from the rear surface and the inner surface of the temple so as to form a portion of a surface of the temple, and the power supply unit is not exposed on an outer surface of the temple which is located on a side opposite to the inner surface of the temple, wherein the electrical connection terminals are disposed at a predetermined interval, and wherein a projection portion having a predetermined height is disposed between the electrical connection terminals; wherein the projection portion extends from a front end of the power supply unit to a front portion of the side surface of the housing unit, and is brought into contact with or fixed to the front portion.