A chip-type light-emitting semiconductor device includes: a substrate 4; a blue LED 1 mounted on the substrate 4; and a luminescent layer 3 made of a mixture of yellow/yellowish phosphor particles 2 and a base material 13 (translucent resin). The yellow/yellowish phosphor particles 2 is a silicate phosphor which absorbs blue light emitted by the blue LED 1 to emit a fluorescence having a main emission peak in the wavelength range from 550 nm to 600 nm, inclusive, and which contains, as a main component, a compound expressed by the chemical formula: (Sr_1-a1-b1-xBa_a1Ca_b1Eu_x)₂SiO₄ (0a10.3, 0b10.8 and 0x1). The silicate phosphor particles disperse substantially evenly in the resin easily. As a result, excellent white light is obtained.