To provide a substrate for a light emitting element in which an increase of heat resistance caused by inner layer wiring is suppressed.

The substrate 1 for a light emitting element includes a substrate body 2 having a mounting surface 21 for mounting the light emitting element 11 and composed of a sintered body of glass ceramic component including glass powder and a ceramics filler, an element connection terminal 3 provided at the mounting surface 21 side of the substrate body 2, an external connection terminal 6 provided at the opposite side of the mounting surface 21 side of the substrate body 2, and the inner layer wiring 4 electrically connected to the element connection terminal 3 and to the external connection terminal 6, and provided nearly in parallel with the mounting surface 21 within a range of 100 μm or smaller from the mounting surface 21. The inner layer wiring 4 is provided so as not to overlap the mounting part for mounting the light emitting element 11.