Question

As we below the surface of earth the value of g is

Answer 1

As we go away from the surface of Earth value of g decreases

As per your question,

Below the surface of earth value of g goes on decreasing

Answer 2

as we go below the earths surface
the value of g goes on decreasing due to factors like radius and mass of the earth.
Hence as we go down in earth,the value of g decreases.