A light emitting element housing package of the present disclosure includes a base part including a first surface including a first recessed part for mounting a light emitting element. Surface roughness Sa of at least such a region of a bottom surface of the first recessed part that is opposite to a light emitting element mounted on the first recessed part is smaller than surface roughness Sa of a region other than the first recessed part of the first surface. Further, a light emitting device of the present disclosure includes the light emitting element housing package and a light emitting element housed in the light emitting element housing package. Further, a light emitting module of the present disclosure includes the light emitting device and a module substrate on which the light emitting device is mounted.