Four LED chips are mounted on a sub-mount substrate so as to be parallel thereto. A wire 9a is installed to extend between a pad electrode 7a of two pad electrodes 7a, 7b provided in two diagonal corners of an upper surface of the LED chip 1 which pad electrode 7a is disposed on a first edge 1a side of the LED chip 1 and a bonding area of a conductive pattern 13 so as to be inclined at 15 to 40 degrees towards an orientation which moves away from a first edge 1a with respect to an orthogonal moving-away direction D relative to the first edge 1a. A wire 9b is installed to extend between the pad electrode 7b which is disposed on a second edge 1b side of the LED chip 1 and a bonding area of the conductive pattern 1 so as to be inclined 15 to 40 degrees towards an orientation which approaches a second edge 1b of the LED chip 1 with respect to an orthogonal moving-away direction D relative to the second edge 1b.