To reduce the possibility of short-circuiting a positive conductor pattern with a negative conductor pattern while enhancing the cooling efficiency of a light emitting element.

This lighting system comprises a LED package 1 in which a negative electrode 1c is disposed on the opposite side of a positive electrode 1b with the light emitting element 1a interposed therebetween and a heat receiving jacket 6 for transferring the heat generated from the light emitting element 1a to a cooling water. An insulation layer 2a is directly joined onto the heat receiving jacket 6. The positive conductor pattern 2b and the negative conductor pattern 2c are formed on the insulation layer. A heat conductive member 3 formed separately from the positive conductor pattern 2b and the negative conductor pattern 2c is disposed between the light emitting element 1a and the heat receiving jacket 6 and between the positive conductor pattern 2b and the negative conductor pattern 2c. An insulation space 4a is arranged between the heat conductive member 3 and the positive conductor pattern 2b, and an insulation space 4b is arranged between the heat conductive member 3 and the negative conductor pattern 2c.