An optical element comprising: a container including a first end face wall and a second end face wall facing each other, a side face wall connecting the first end face wall to the second end face wall, and a hermetically sealed accommodating chamber provided inside the end face walls (24,26) and the side face wall; a first liquid enclosed in the accommodating chamber; a second liquid immiscible with the first liquid and enclosed in the accommodating chamber; a first electrode and a second electrode; an insulating film between the second electrode and the second liquid; and wherein the transmittance of the first liquid is lower than the transmittance of the second liquid, the shape of an interface between the first liquid and the second liquid is changed by the application of a voltage between the first electrode and the second electrode through an electro-wetting phenomenon, and a light transmission path, the center of which is a single virtual axis passing through the first end face wall and the second end face wall and extending in the thickness direction of the container, which is a direction in which the first end face wall and the second end face wall face each other, is formed in a portion of the second liquid, the first electrode is provided on an inner surface of the first end face wall, the inner surface facing the accommodating chamber, the second electrode is provided on an inner surface of the second end face wall, the inner surface facing the accommodating chamber, the insulating film is provided on a surface of the second electrode, the surface facing the accommodating chamber, and when viewed from the thickness direction of the container, an opening (42,44) having a diameter the same as or smaller than the maximum diameter (Dmax) of the transmission path, the center of which is the virtual axis, is provided in the second electrode or in each of the second electrode and the insulating film. a container including a first end face wall and a second end face wall facing each other, a side face wall connecting the first end face wall to the second end face wall, and a hermetically sealed accommodating chamber provided inside the end face walls (24,26) and the side face wall; a first liquid enclosed in the accommodating chamber; a second liquid immiscible with the first liquid and enclosed in the accommodating chamber; a first electrode and a second electrode; an insulating film between the second electrode and the second liquid; and wherein the transmittance of the first liquid is lower than the transmittance of the second liquid, the shape of an interface between the first liquid and the second liquid is changed by the application of a voltage between the first electrode and the second electrode through an electro-wetting phenomenon, and a light transmission path, the center of which is a single virtual axis passing through the first end face wall and the second end face wall and extending in the thickness direction of the container, which is a direction in which the first end face wall and the second end face wall face each other, is formed in a portion of the second liquid, the first electrode is provided on an inner surface of the first end face wall, the inner surface facing the accommodating chamber, the second electrode is provided on an inner surface of the second end face wall, the inner surface facing the accommodating chamber, the insulating film is provided on a surface of the second electrode, the surface facing the accommodating chamber, and when viewed from the thickness direction of the container, an opening (42,44) having a diameter the same as or smaller than the maximum diameter (Dmax) of the transmission path, the center of which is the virtual axis, is provided in the second electrode or in each of the second electrode and the insulating film.