An input operation device comprising: a substrate; a first light-emitting section disposed on an upper surface of the substrate; a second light-emitting section disposed on the upper surface of the substrate; a third light-emitting section disposed on the upper surface of the substrate; a first light guide body which has an upper surface section and a side surface section, and has a first mark and a second mark; and a second light guide body having an upper surface section and a side surface section, wherein an upper end of the side surface section of the first light guide body is connected to the upper surface section of the first light guide body, and a lower end of the side surface section of the first light guide body faces the first light-emitting section and the second light-emitting section, the first mark emits light on the upper surface section of the first light guide body when light is incident on the first light guide body from the first light-emitting section, the second mark emits light on the upper surface section of the first light guide body when light is incident on the first light guide body from the second light-emitting section, the upper surface section of the second light guide body emits light when light is incident on the second light guide body from the third light-emitting section, and at least one of the first light-emitting section, the second light-emitting section, and the third light-emitting section is capable of changing light emission luminance, characterized in that the first mark and the second mark are formed on a lower surface of the upper surface section of the first light guide body, and in that on the first light guide body, a region where the first mark is formed and a region where the second mark is formed are at least partially overlapped with each other. a substrate; a first light-emitting section disposed on an upper surface of the substrate; a second light-emitting section disposed on the upper surface of the substrate; a third light-emitting section disposed on the upper surface of the substrate; a first light guide body which has an upper surface section and a side surface section, and has a first mark and a second mark; and a second light guide body having an upper surface section and a side surface section, wherein an upper end of the side surface section of the first light guide body is connected to the upper surface section of the first light guide body, and a lower end of the side surface section of the first light guide body faces the first light-emitting section and the second light-emitting section, the first mark emits light on the upper surface section of the first light guide body when light is incident on the first light guide body from the first light-emitting section, the second mark emits light on the upper surface section of the first light guide body when light is incident on the first light guide body from the second light-emitting section, the upper surface section of the second light guide body emits light when light is incident on the second light guide body from the third light-emitting section, and at least one of the first light-emitting section, the second light-emitting section, and the third light-emitting section is capable of changing light emission luminance, characterized in that the first mark and the second mark are formed on a lower surface of the upper surface section of the first light guide body, and in that on the first light guide body, a region where the first mark is formed and a region where the second mark is formed are at least partially overlapped with each other.