A light source module includes a circuit board, light emitting diode chips on an upper surface of the circuit board, the light emitting diode chips being spaced apart and each emitting blue light and having a first surface facing the upper surface of the circuit board, a second surface opposite the first surface, and first and second electrodes on the first surface, a first multilayer reflective structure on the second surface and including a plurality of alternately stacked insulating layers having different refractive indices, and a lens respectively covering each of the light emitting diode chips and contacting the upper surface of the circuit board at an acute contact angle, the lens having a thickness of 2.5 mm or less from the upper surface of the circuit board, and a contact region with the upper surface of the circuit board with a diameter of 1 mm to 3 mm.