A wavelength-converting member includes a wavelength-converting layer, a heat-dissipating component, and a securing member. The wavelength-converting layer has an upper surface, a lower surface, and one or more lateral surfaces with each of the one or more lateral surfaces of the wavelength-converting layer defining an inclined surface inclined at an acute angle with respect to the lower surface of the wavelength-converting layer. The wavelength-converting layer includes a thermally conductive part, and a fluorescent material containing part in contact with the thermally conductive part. The wavelength-converting layer is mounted on the heat-dissipating component. The securing member is secured to the heat-dissipating component. The securing member presses the inclined surface of each of the one or more lateral surfaces such that the wavelength-converting layer is secured to the heat-dissipating component.