An optical fiber inspecting device comprising: a first light-emitting unit that is configured to irradiate an optical fiber with a first light beam, the optical fiber including a glass fiber and a coating resin and moving in an axial direction; a first light-receiving unit that is configured to receive scattered light resulting from the first light beam scattered in the optical fiber, and to convert the scattered light to an electrical signal, wherein an optical axis of the first light-receiving unit passes through an irradiation position where the first light beam strikes the optical fiber, and the first light beam and the optical axis of the first light-receiving unit diagonally intersect each other, thereby preventing the first light beam from directly entering the first light-receiving unit, a second light-emitting unit that is configured to irradiate the optical fiber with a second light beam; and a second light-receiving unit that is configured to receive scattered light resulting from the second light beam scattered in the optical fiber, and converts the scattered light to an electrical signal, wherein an optical axis of the second light-receiving unit passes through an irradiation position where the second light beam strikes the optical fiber, and the second light beam and the optical axis of the second light-receiving unit diagonally intersect each other, thereby preventing the second light beam from directly entering the second light-receiving unit, wherein a position irradiated with the first light beam from the first light-emitting unit and a position irradiated with the second light beam from the second light-emitting unit are different each other along the axial direction of the optical fiber; and wherein an output wavelength of light emitted from each light-emitting unit corresponds to infrared light having a wavelength band 1000 nm or more. a first light-emitting unit that is configured to irradiate an optical fiber with a first light beam, the optical fiber including a glass fiber and a coating resin and moving in an axial direction; a first light-receiving unit that is configured to receive scattered light resulting from the first light beam scattered in the optical fiber, and to convert the scattered light to an electrical signal, wherein an optical axis of the first light-receiving unit passes through an irradiation position where the first light beam strikes the optical fiber, and the first light beam and the optical axis of the first light-receiving unit diagonally intersect each other, thereby preventing the first light beam from directly entering the first light-receiving unit, a second light-emitting unit that is configured to irradiate the optical fiber with a second light beam; and a second light-receiving unit that is configured to receive scattered light resulting from the second light beam scattered in the optical fiber, and converts the scattered light to an electrical signal, wherein an optical axis of the second light-receiving unit passes through an irradiation position where the second light beam strikes the optical fiber, and the second light beam and the optical axis of the second light-receiving unit diagonally intersect each other, thereby preventing the second light beam from directly entering the second light-receiving unit, wherein a position irradiated with the first light beam from the first light-emitting unit and a position irradiated with the second light beam from the second light-emitting unit are different each other along the axial direction of the optical fiber; and wherein an output wavelength of light emitted from each light-emitting unit corresponds to infrared light having a wavelength band 1000 nm or more.