Wavelength conversion member and light-emitting device

A transmissive-type wavelength conversion member that converts light with a wavelength in a specific range to light with a different wavelength and allows light passing through the wavelength conversion member to be used as illuminating light, the wavelength conversion member being characterized by comprising:

• a substrate that is formed of an inorganic material and allows light to pass therethrough;
• and
• a fluorescent material layer disposed on the substrate, the fluorescent material layer including fluorescent material particles that absorb light and emit converted light and a light-transmitting ceramic that bonds the fluorescent material particles together,
• wherein a ratio of a thickness of the fluorescent material layer to an average particle diameter of the fluorescent material particles is equal to or more than 1.5 and less than 30,
• wherein, when source light having a wavelength in a specific range and a power density of 5 W/mm2 is used, an intensity of fluorescence from the fluorescent material layer is at least 50% of a maximum fluorescence intensity of the fluorescent material layer, and
• wherein the fluorescent material layer has a porosity of 30 to 70%, the porosity being defined as the ratio of the volume of pore portions in a constant-thickness layer section to the apparent volume of the constant-thickness layer section, the constant-thickness layer section being sandwiched between a plane in contact with the surface of an outermost one of the fluorescent material particles and a plane in contact with the substrate, the volume of the pore portions being computed by subtracting the volume of a solid component included in the apparent volume from the apparent volume.