  We establish an exact formulation for wave scattering of a massless field
with spin and charge by Kerr-Newman-de Sitter black hole. Our formulation is
based on the exact solution of the Teukolsky equation in terms of the local
Heun function, and does not require any approximation. It serves simple exact
formulae with arbitrary high precision, which realize fast calculation without
restrictions on model parameters. We highlight several applications including
the quasinormal modes, cross section, reflection/absorption rate, and Green
function.
